Английский словарь американских идиом - excuse oneself

{v. phr.} 1. To think of reasons for not being to blame; think yourself not at fault. * /John excused himself for his low grades on the ground that the teacher didn't like him./ 2. To ask to be excused after doing something impolite. * /John excused himself for his tardiness, saying his watch was wrong./ 3. To ask permission to leave a group or place. * /The committee meeting lasted so long that Mr. Wilkins excused himself to keep an appointment./ * /John had to go to the dentist's, so he excused himself and left the classroom./