combination number
nounUK /ˌkɒmbɪˈneɪʃən ˈnʌmbə/
US /ˌkɑːmbəˈneɪʃən ˈnʌmbər/
A combination number is a secret set of numbers you use to open a lock.
She forgot the combination number for her bike lock.
OTHER MEANINGS
2. A number that shows how many different groups can be chosen from a larger set.
In math class we learned how to find the combination number for picking three cards from a deck.
3. A number used to identify a particular combination of items, such as in a catalog or lottery.
Check the combination number on the ticket to see if you won.
4. A sequence of numbers dialed to open a combination lock.
He spun the dial to enter the combination number and the lock clicked open.