1 general:: Phrase(s): (I’d) better get on my horse. Inf. an expression indicating that it is time that one departed. • John: It’s getting late. Better get on my horse. Rachel: Have a safe trip. See you tomorrow. • "I’d better get on my horse. The sun’ll be down in an hour," said Sue, sounding like a cowboy.
McGrawhill's American Idioms And Phrasal Verbs