Lightweight
Someone that freaks out or has adverse effects that other people around them don't have on a light amount of a drink or substance (not just once but always, something they're known for) is about as close you get to what somebody means when they say somebody is a lightweight. So a guy drinking a quart of wine and not being able to stand up is not a lightweight, because most people shouldn't have good balance after drinking a quart of wine.
The lightweight is falling all over the place or making a chaotic environment every time he/she has a couple shots or beers, or hits of a joint.
Lightweight by The Original Agahnim June 17, 2021
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