"gar" means "expressing a choice between alternatives" (if, whether), "digar" can be compared to "magar" which means "but, other, unless".Not sure about the exact etymology, but Tolman compares it in his Old Persian dictionary with O.P. duvitīya (Skt. dvitīya-), "second". So, I guess, at least he takes the initial di- of digar to be related to PIE *dwo- (two). No idea about the -gar part.
Persian دیگر (digar) – other, another.The NP نيز/niz means "also", isn't its final iz the same, if so, what does /n/ mean?
They are not similar words but the same word. Persian and Tajik are the same language. Azerbaijani and Turkish borrowed it from Persian along with a few other thousand words during the last 1500 years when they were in contact with or present in Persophone lands.Persian ... Tajik ... Turkish ... Azerbaijani
The clue is in the Azerbaijani word "digərgün" – 1. other, another; 2. changed, altered.You obviously don't agree with contents of posts #2, 3, 6 above, you then must have a counter argument of similar quality & detail, that argues 'digar' is of Turkish origin & not a straight forward borrowing from Persian.
дикарь is an adjective constructed from the root ди́кии́ (free, wild) whose cognates are seemingly found across Slavic languages (which Russian belongs to). They are only distantly related to Persian/Tajik. Russian or any Slavic language wasn't in a position to loan to Persian/Tajik before 1700s, apart from their ethnonyms. Tajik is the same language as Persian with only a few differences in the choice of words and accent, and some recently borrowed words which doesn't include the millennia-old digar.Here is another similar word. Russian «дикарь» (dikar) – a savage.
It's another Persian loanword. Persian gūn[e] means "feature" or "color". It is a common suffix found in many other Persian words meaning "like" (e.g., īn-gūne "this way", nīl-gūn "color of lapis lazuli", āb-gūn "like water", and of course dīgargūn or degargūn meaning "altered" which is attested in Persian long before there was something called Azerbaijani language). Cognates of gūn[e] have been attested in Indo-Iranian languages from 3000 years ago (Sanskrit guṇa).The clue is in the Azerbaijani word "digərgün" – 1. other, another; 2. changed, altered.