<p><strong>noun</strong></p><ul><li>a small body of standing water; pond.</li><li>a still, deep place in a stream.</li><li>any small collection of liquid on a surface: a pool of blood.</li><li>a puddle.</li><li>swimming pool.</li><li>a subterranean accumulation of oil or gas held in porous and permeable sedimentary rock reservoir.</li></ul><p><strong>verb</strong></p><ul><li>(used without object) to form a pool.</li><li>(of blood) to accumulate in a body part or organ.</li><li>(used with object) to cause pools to form in.</li><li>to cause (blood) to form pools.</li></ul><p><strong>adjective</strong></p><ul><li>of or for a pool: pool filters.</li><li>taking place or occurring around or near a pool: a pool party.</li></ul>