Fig. to keep talking or complaining about someone or something; to refer to someone or something again and again. I wish you would quit harping on Jeff all the time. He couldn't be all that bad.Stop harping on my mistakes and work on your own.
Dwell on; talk or write about to a tedious and excessive extent. For example, She kept harping on the fact that she had no household help at all. This expression is a shortening of harp on the same string, meaning "to play the same note over and over." It was first recorded in 1518.
To talk about something to an excessive and tedious degree; dwell on something: Every day my teacher harps on the importance of getting to class on time.