What does brown-nose mean?

brown-nose meaning in Etymology Dictionary

additionally brownnose, 1939, American English colloquial, considered army slang originally, from brown (adj.) + nostrils (n.), "from the implication that servility is tantamount to presenting your nostrils inside anus of the person from whom development is looked for" [Webster, 1961]. Relevant: Brown-noser, brown-nosing (both 1950).

brown-nose meaning in General Dictionary

flatter because of the intention of having some thing