flat tire
noun
a pneumatic tire that has lost all or most of its air through leakage, puncture, or the like.
Older Slang.
a dull or socially inept person.
Origin of flat tire
First recorded in 1920–25
Words nearby flat tire
flat silver,
flat sour,
flat spin,
flat spot,
flat tax,
flat tire,
flat top,
flat tuning,
flat universe,
flat wart,
flat white