skeleton key 
noun
A key designed to fit many locks by having the interior of the bit hollowed.He slid a skeleton key into the lock, and eased the door open....
- Officer Humphrey put the skeleton key into the lock in order to get the door open.
- Taking a sharp breath in, she opened the package and found a heart shaped locket key chain with a skeleton key.
- aspirant
- aspirate
- aspiration
- aspirational
- aspirationally
- aspirational voter
- aspirator
- aspire
- aspirin
- aspiring
- (as) pissed as a newt (or fart)
- (as) plain as a pikestaff
- as plain as the nose on someone's face
- (as) pleased as Punch
- as pleased (or proud) as Punch
- (as) poor as a church mouse
- asportation
- a sprat to catch a mackerel
- asprawl
- (as) pretty as a picture
- asp viper
- a square deal
- a square peg in a round hole
- (as) quick as a flash
- (as) quiet as a mouse (or lamb)