From Wiktionary, the free dictionary
See -nok.
-nök
- (noun-forming suffix) Front-vowel variant of -nok: Added to a word to form the name of an occupation.
- mér (“to measure”) + -nök → mérnök (“engineer”)
- ügy (“matter”) + -nök → ügynök (“agent”)
- (noun-forming suffix) Variants:
- -nok is added to back-vowel words
- dal (“song”) + -nok → dalnok (“singer”)
- -nek is added to unrounded front-vowel words
- eretnek (“heretic”)
- -nök is added to rounded and some unrounded front-vowel words
- ügy (“matter”) + -nök → ügynök (“agent”)
- mér (“to measure”) + -nök → mérnök (“engineer”)