SUE
She sued him (her husband) for a divorce.

NOD OFF
1) I was so sleepy that I nodded off.
2) We both nodded off in front of the TV.

RUTHLESS
1) The political power was in the hands of a few ruthless men.
2) You can´t trust him because he is a ruthless tactician.

DROWSY
1) I felt drowsy after the long drive.
2) A drowsy driver may be as dangerous as a drunk behind the wheel.