Presumptuous and insulting in manner or speech; arrogant.
Audaciously rude or disrespectful; impertinent.
[Middle English, from Latin īnsolēns, īnsolent-, immoderate, arrogant : in-, not; see in-1 + solēns, present participle of solēre, to be accustomed.] in'so·lent n., in'so·lent·ly adv.