Blow Up Sth English Meaning Release Air Tyre Mattress

Meaning: to release the air from something like a tyre or a blow-up mattress

• let down sth Timothy was expelled from school for letting down the tyres on his teacher's car.
  
  
• let sth down After they'd played with their blow-up dolls, they let them down and packed them away.
  
  

Variety: Thisis typically used in British and Australian English but may be used in other varieties of English too.