Expressions (phrases, clauses, etc.), Godan verb with 'ku' ending
to encourage to do (something); to urge a person on; to demand action
Idiomatic expression
佐藤さんは息子の尻をたたいて勉強させた。Mrs. Sato pushed her son to study hard. to spank; to give a spanking; to hit someone on the bottom; to beat someone's backside
Also written 尻を叩く【しりをたたく】