| Geyser (n.) A boiling spring which throws forth at frequent intervals jets of water, mud, etc., driven up by the expansive power of steam. Thesaurus Entries Old Faithful, boiling water, flush, font, fount, fountain, gush, hot spring, hot water, jet, rush, spew, spit, spout, spouter, spray, spritz, spurt, spurtle, squirt, steam, thermae, vapor | ![]() |