Burns up the telephone line, 4 letters
Goes on and on and on, 4 letters
Is a voluble member of society?, 4 letters
Runs off at the mouth, 4 letters
Runs up a big phone bill, in a way, 4 letters
Talks a blue streak, 4 letters
Talks and talks and talks, 4 letters
Talks one's ear off, 4 letters
Talks, talks, talks, 4 letters
Ties up the phone line, 4 letters
Ties up the phone, say, 4 letters