Ee Han Timing
From Liquipedia StarCraft Brood War Wiki
Ee han timing stands for a timing in the game where you have to do damage. For example 2 hatch mutalisks. By doing this build you are (usually) behind economic wise. Therefore you have to do damage or else you will be significantly behind. It is an ee han timing moment. Ee han timing can be translated roughly into 'This one timing'
Also see Timing Window