Uppity describes somebody behaving as though they are above their station. Answering back, taking a tone, forgetting their place.
The word is worth knowing chiefly for what it reveals about whoever uses it, since calling a person uppity says they should have stayed quiet and deferred. In American English it carries a specific and ugly racial history, having been used against Black people who refused to defer. It is informal, dated and best understood rather than reached for. English has plenty of neutral alternatives, including arrogant and presumptuous.
1adjectiveuppityBehaving as though above your proper place, in the speaker's view.
“He complained that the new clerk was getting uppity.”
From earlier uppedy, equivalent to up + -ed + -y; compare blackity, biggity, and hippity (and possibly also persnickety, pernickety). First attested around 1880 in Uncle Remus by Joel Chandler Harris to describe Jack Sparrer (Jack Sparrow), who tattled on Br'er Rabbit (see quotations below). Compare uppish.
Etymology from Wiktionary, CC BY-SA