gutless adjective 2phrases 1 adjective2 •Without a gut.This approach was firstly used in a metagenomic context to study the microbial community associated with the gutless worm Olavius algarvensis. — 2015 •(informal) Cowardly; lacking courage or morals.No, you lied to me. You lied to me because you're gutless. You're a gutless drunken loser. — 1996 Phrases with gutless gutless wonderOne who lacks guts or courage; a coward.