1) For a small child, undershirt and underpants which button together at the waist.
2) An effeminate man, derogatory.
1) My kid is dressed in a pantywaist, dress and mary-Janes.
2) That wus is an obvious pantywaist.
A feminine, limp-wristed guy who lacks courage. May or may not be gay, but is usually assumed to be.
"Jimmy swears that he likes chicks, even though he's such an obvious pantywaist."
That guy is such a panty waist, he's afraid of everything.
(Noun)-(Pan tee wayst)One who's manlihood is in question. A Sally. A bitch. Of military origin.
Soldier 1:"Hey lets go find some whores!"
Soldier 2: "No thanks my feet hurt, I just want some chow and a bubble bath."
Soldier 1: "You fucking panty waist!"