Your a Thumb

Best definition
Your a Thumb
1). A playful phrase spoken to friends as a term of endearment. The phrase “your a thumb” roughly means “your dumb” and is spoken to friends to emphasize their flaws, in a loving way.2). The phrase “your a thumb” may also mean “you have a big forehead”
1) Katie: *falls*

Malia: “YOUR A THUMB”

2) Malia: “Brendon has such a big forehead”

Katie: “He’s such a thumb”