expression, godan verb (-ru)
talk on and on; talk one's head off
Emphatic compound of 喋る (to chat) and まくる (to do something continuously or intensely). Conveys talking nonstop, often excessively or excitedly.
彼は昨日のパーティーのことをしゃべりまくった。
He talked on and on about yesterday's party.
電
I talked my head off with a friend on the phone, and before I knew it two hours had passed.