Polish Language/Polish Equivalent and Diminutives for William
Hello there! First and foremost, thank you for your involvement with this service; your answers are very substantive and informative!
I'm a third-generation Polish-American with a spontaneous itch to learn the language and culture of my community. I live in one of the rare places in the United States where Polish is comparatively widely spoken, yet in all my interactions and explorations I've never encountered a Polish equivalent to the name William; some sources (aka Google) suggest that it's Wilhelm with the diminutive Wiluś, but I've never met a Polish Wilhelm and the only usages of the name "Wiluś" I've found are pejorative references to Kaiser Wilhelm II, and a more innocuous rendition of Wile E. Coyote.
Are these truly the Polish equivalents of William and Will, Bill, etc. that have just fallen out of popular usage, or have I missed the mark entirely?
you are right in all your remarks, yet each of them requires some comments.
a) The Polish equivalent of William is Wilhelm and its diminutive is Wiluś. It is not the only theoretically possible one, the other one met with is "Lusiek". You can also imagine people using other diminutives like Wilek, Wilcio, Helmek or Elmek, Elmuś, etc. (read some of my previous posts for the notion of "private diminutives" or "family owned ones") but Wiluś is certainly the most popular and most obvious one.
b) Wilhelm seems to be a very rare name in modern Polish, myself I have also never met any Wilhelm in real life, yet I have met two Wilhelminas (one of them was an elderly lady even then, i.e. in ca. 1970-75; the other one was younger than me by about 5-7 years, i.e. born ca. 1965), and I have heard quite recently (2-3 years ago) that some relatives of my colleague have given this name to their new-born daughter, and "Wilhelmina" is just a female equivalent of "Wilhelm". And I remember that in a Polish movie of the last decade thare is a character, a 10-year old girl with the name "Wilhelmina" (maybe this movie was the reason .
The reason might be that the name is very often associated with Kaiser Wilhelm, which was considered a "Pole-monger" (alongside with Bismarck), and at the same time "flatterer of Poles"
Similarly you will not meet any Adolf now in Poland (because of Hitler), yet it was quite a popular name before the WWII (see e.g. famous actor and Singer Adolf Dymsza). Kaiser Wilhelm was considered arrogant and full of false pride, irresponsible (responsible for the break out of the WWI, and the dectruction of the German Empire, he has never admitted or accepted to feel any guilt or shame because of that). His 3 visits to Poznan, and the visit to Częstochowa in 1915 are mentioned as the signs of his utter arrogance.
MAYBE this is the reason of the low popularity now. He was especially loved by ones and hated by others in Wielkopolska (Greater Poland region, with Poznań as a capital) and in Silesia, and later hated by all. But on the other hand, who remembers Kaiser Wilhelm and has any emotional realtion to him any more? (And who really knows what causes some names to become popular at some time and unpopular at some other time?).
On the contrary the name itself must have been quite popular in Górny Śląsk (Upper Silesia), with Katowice as the capital and Opole as the other main center, because it appears in several Silesian regional stories and fables, and there mostly in the form of "Wiluś" or "Wili" (see: e.g. http://allegro.pl/biblia-tuwim-kuchnia-bojki-elem-szoltysek-autograf-i5761825216
). And a famous Silesian poet and writer was Wlhelm Szewczyk (1916-1991), see: https://pl.wikipedia.org/wiki/Wilhelm_Szewczyk, http://www.bibliofilur.republika.pl/album/LS.htm
According to the official statistics of Polish names (made by the Ministry of Interior and Public Administration after the official registries cntained in the PESEL database, see: https://mswia.gov.pl/pl/sprawy-obywatelskie/statystyki-imion-i-nazw - in the section: "Najczęściej i najrzadziej nadawane imiona dzieciom w 2014 r. z podziałem na województwo rejestracji urodzenia i płeć, ze wskazaniem liczby wystąpień" (The most often and the most rare names given to children born in 2014, divided by the voivodship [region] of birth and sex, giving the number of events) tell us that in 2014 6 newly born boys were named "Wilhelm" (all of them in Mazowsze / Mazovia region with the capital in Warsaw) and seemingly no girls were named "Wilhelmina".
The name must have been quite commmon in earlier times as several princes or dukes of Silesia had this name (See:
https://pl.wikipedia.org/w/index.php?search=wilhelm&title=Specjalna:Szukaj&go=Przejd%C5%BA&searchToken=20txj87ezmwmk2dvxjvmr3zjn ). Among other famous "Wilhelms" (not necessarily of Polish nationality), known to many Poles, you may find "Wilhelm Tell" and "Wilhelm Zdobywca". And the nameday of Wilhelm in the Polish calendar appears too many times for an unpopular name: Jan.1, Jan.10, Feb.7, Feb.10, Feb.17, Apr. 6, May 17, June 8, July 26, July 29 and Sep. 2 (according to Wikipedia: https://pl.wikipedia.org/wiki/Wilhelm), the most popular being that on Sept 2. [St. William of Roskilde], next those on January 10 [St. William of Donjeon/Dungeon de Bourges] and April 6 [St. Guillaume de Paris = St. William of Eskil];
Wilhelmina's nameday is only once: Sep. 22 [St. Emilia Maria Wilhelmina de Rodat] (https://pl.wikipedia.org/wiki/Wilhelmina_%28imi%C4%99%29).
The other sign of its former popularity is the surname "Wilhelmi". https://pl.wikipedia.org/w/index.php?title=Specjalna:Szukaj&limit=500&offset=0&ns0=1&ns1=1&search=wilhelmi&searchToken=d9za67mqrmhfcfuy0vhwz4xp9, among them - the famous Polish film and theatre actor, Roman Wilhelmi (1936-1991) and infamous Marxist politician Janusz Wilhelmi (1927-1978) - Minister of Culture 1977-1978 who was trying to destroy all independent Polish culture, not only anti-Marxist but also purely non-idelogical (especially film, television and radio), but thank God soon died in a plane crash. Present day (2001) distribution of this surname, see: http://www.moikrewni.pl/mapa/kompletny/wilhelmi.html
"Wilhelmi" is an adjective from Wilhelm, so the surname means "belonging to Wilhelm", or "follower of Wilhelm" or "descendant of Wilhelm".
c) "Wiluś" was used originally as a endearing nickname for the Kasier, invented by some journalist in Poznań during his firt visit to Poznań when he started building the Royal Castle in Poznan and tried to flatter the majoritary Polish population of the Region. It has finally become a pejorative nickname for him used in all three parts of partitioned Poland. In fact, any diminutive can be used as a pejorative appellation, not only Wiluś. Diminutives, or endearment forms, carry a load of emotions, and a passage from love to hatred is just one step (compare a famous Rubaiyat of Omar Khayyam on this subject). In fact the usage here (for the Kaiser Wilhelm II) is not so much pejorative but rather mocking, a kind of "magical" approach to diminish the fear. When someone is your enemy, and a powerful one, the way to psychologically diminish your fear and his power is to treat him like a small child, not like a grown up man, by calling him with a diminutive (the way that is always appropriate while addressing children or talking about children; when adults concerned - rather only among close friends and relatives). Thus usage of a diminutive becomes a form of joke, a kind of linguistic equivalent to a caricature in drawing/painting. See: http://meteor2017.blogspot.com/2015/02/cesarz-nad-rawka-i-bzura.html
But if, for the reason that it is most often associated with the Kaiser mentioned, you don't like beich called "Wiluś", choose the form "Lusiek" for yourself and it will be perfectly well understood.
All the best
P.S. I have not heard about Wile. E. Coyote being called "Wiluś" until having checked your information. In fact I have watched the cartoons in English long long time ago and have never seen then in Polish. The other fact is that I even didn't remember that the main character of these cartoons id called Wile E. Coyote. The other fact is that the diminutive "wiluś" may be considered a diminutive for "wilk" (wolf), along with the others, more common, like wilczek. A coyote is an animal unknown in Poland (unless from some travel stories and Western movies), and the animal looks more or less like a wolf (or a caricature of a wolf), a typical negative hero of European fables, starting with the "Czerwony Kapturek" (or "Little Red Riding Hood") or even with Aesop. See e.g. the Russian cartoon "The Wolf and the Hare" (or "Nu pogodi!" https://en.wikipedia.org/wiki/Nu,_pogodi!) more commonnly watched in Poland at the times of my youth and that of my children.