Adjective
(slang, derogatory) Overly talkative, insolent, and loud.
Synonym: gobby
Of a dog: inclined to bite or nip.
Synonyms: bitey, nippy
Selena was seen hanging all over The Weeknd Tuesday night outside Giorgio Baldi in Santa Monica -- getting handsy and mouthy with the singer. Source: Internet
She's a little more mouthy than I was when I was a kid. Source: Internet
Mouthy, brutal, good on the ball… a great centre back. Source: Internet