1
general::
Phrase(s): horse around (with someone or something)
1. Fig. to play around roughly with someone or something, possibly abusing someone or something. • Stop horsing around with your little brother. Leave him alone. • Will you kids stop horsing around? 2. Fig. to join someone in boisterous play; to participate in rough play with someone. • He’s horsing around with his little brother. They are really having a good time. • We spent the entire afternoon just horsing around.
McGrawhill's American Idioms And Phrasal Verbs
2
general::
Indulge in frivolous activity or play. For example, The boys were horsing around all afternoon. This term presumably alludes to horseplay, which has meant "rough or boisterous play" since the late 1500s. [First half of 1900s]
American Heritage Idioms