The act of supplying.

“supply and demand”

An amount of something supplied.

“A supply of good drinking water is essential.”

(in the plural) provisions.

To provide (something), to make (something) available for use.

“to supply money for the war”

To furnish or equip with.

“to supply a furnace with fuel; to supply soldiers with ammunition”

To fill up, or keep full.

“Rivers are supplied by smaller streams.”