not hold (your) liquor

to not be able to drink alcohol without showing any effects.

Scott didn't hold his liquor very well — he'd either fall asleep or sit silently and sadly after a couple of drinks.

Usage notes: the opposite meaning is expressed by hold your liquor:

Now there's a gang that can hold their liquor!

• not have a leg to stand on
• not have a minute to call own
• not have a minute to call your own
• not have a monopoly on
• not have a monopoly on something
• not have a pot to piss in
• not have a prayer
• not have a snowball's chance in hell
• not have a type of bone in body
• not have a type of bone in your body
• not have much going for
• not have much going for you
• not have much time
• not have much time someone
• not have much time something
• not have the faintest
• not have the faintest idea
• not have the foggiest idea
• not have the foggiest notion
• not have the heart
• not have the heart to
• not have the heart to do something
• not have the stomach
• not have the stomach for
• not have the stomach for something