flat tyre

noun3

1. •
   A tyre of a motor vehicle that is deflated, especially one deflated because of a puncture when in use.
2. •
   The result of stepping on the back of another individual's shoe in an accidental act, or deliberately to bully or tease this person, so as to cause the back of the shoe to collapse under the heel.
3. •
   (slang, old-fashioned) A bore; a person who is no fun.

   • Sam scowled at him. “You're always such a flat tire. Live a little for once.” A twinge of pity for Judd made Carrie speak. “He's not a flat tire. He just doesn't want to.” — 2020