What it means
The supposed opposite of an alpha: the meek, deferential follower who lets others lead and never makes the first move. Used as a put-down for being passive or a pushover, and almost always with the same eye-roll the whole alpha-beta hierarchy now earns. Heavily ironic these days.
Usage examples
"He apologised for being in his own seat, peak beta move."
"Letting the loud guy decide everything is a bit beta, just say what you want."
"Bro let them send his food back twice and still said sorry, that's insanely beta."
"Calling yourself an alpha unironically is bad enough, but acting all beta right after is killing me."
Where it comes from
It comes from beta in the old alpha-beta pecking-order idea people borrowed from animal behaviour talk. That whole macho hierarchy got picked apart years ago, but beta survived online and in slang as a jab for someone seen as weak, passive, timid, or too easy to walk over.
