Expressions (phrases, clauses, etc.), Godan verb with 'ku' ending
to boast; to brag; to talk big
トムと飲みに行くんだったら、突拍子もないホラを吹くだろうから、覚悟した方がいいよ。If you go drinking with Tom, be prepared to listen to some pretty outlandish cock and bull stories.
Also written 法螺を吹く【ほらをふく】