WOW

I. interjection Date: 1513 — used to express strong feeling (as pleasure or surprise) II. noun Date: 1920 a striking success ; hit , III. transitive verb Date: 1924 to excite to enthusiastic admiration or approval , IV. noun Etymology: imitative Date: 1932 a distortion in reproduced sound consisting of a slow rise and fall of pitch caused by speed variation in the reproducing system