Open-Limp

betting

Limping in (calling the BB) when you’re first to act preflop.

Almost universally a leak. Strong players raise or fold.

See also

All-In
Betting all your remaining chips.
Ante
A forced bet all players must post before each hand.
Barrel
A continuation bet on a later street (double = flop+turn, triple = + river).
Blind
A forced bet posted before the cards are dealt.