Typically a beta male AFC (average frustrated chump) who is usually a very boring, needy, possessive and jealous to his girlfriend. Kind of a nice guy.
This kind of man has very few qualities that women find attractive, and women usually stick around only until their options open up, when they opt for a more suitable alpha male.
Jenny dumped her borefriend for that PUA dude.
John is the alpha dude who liberated Ayako from her borefriend.
A friends annoying boyfriend who blathers on and on about himself, his stupid job, his watch collection,how many calories he has eaten today, etc.
My friend Mary brought her borefriend to dinner which completely killed the whole vibe of our dinner party.