Pool meaning : A small and rather deep collection of (usually) fresh water, as one supplied by a spring, or occurring in the course of a stream; a reservoir for water. A small body of standing or stagnant water; a puddle. A supply of resources. (by extension) A set of resources that are kept ready to use. A small amount of liquid on a surface. A localized glow of light. (of a liquid) To form a pool. A pool of water used for swimming, usually one which has been artificially constructed.