Meaning of “supply” - Learner’s Dictionary

supply

noun uk us /səˈplaɪ/
AMOUNT [ C ]

B2 an amount of something that is ready to be used:

a supply of water
food supplies
in short supply

If something is in short supply, there is little of it available.

SYSTEM [ C ]

the system of supplying something to people:

Someone has turned off the electricity supply.

(Definition of “supply noun” from the Cambridge Learner’s Dictionary © Cambridge University Press)