I am interested about idiom horse around. Where is it from?
Idioms: horse around
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]
Meaning #1: indulge in horseplay
Synonyms: arse around, fool around, fool