Where does “-нячка” come from?

-нячка (Ukrainian) comes from Russian -ня́к, from Ukrainian -ни́й, from Proto-Slavic -ьnъ — -ish, -ic, -al, -ed; From adjectives.

Ancestry of “-нячка”, step by step

StepLanguageWordMeaning
1Russian-ня́к—
2Ukrainian-ни́йUsed to form adjectives from nouns; -ish, -y
3Proto-Slavic-ьnъ-ish, -ic, -al, -ed; From adjectives
Every word from Proto-Slavic -ьnъ →Every word from Ukrainian -ни́й →Every word from Russian -ня́к →
-нячка — Etymology, Origin & Word History | Etymology Explorer