There are a few you need to know:
A2M - ass to mat. This is used to describe squat depth well below parallel. In the gym you should always be going A2M.
BBC - barbell competence. This is to describe someone with a base level of strength in the gym. All lifters should strive to get BBC as soon as possible. Getting BBC in the gym is reallly important.
BBW - barbell whipping. Used to describe the triple extension that initiates an Olympic lift. It’s important to really thrust your hips hard and fast into a BBW.
Creampie - when your chalked hands tear a callous, usually deadlifting. Getting creampied in the gym is a badge of honour. All the big strong dudes you see in a gym have been creampied at some stage. Ask them if you don’t believe me.
There’s probably more but those are some important examples