Etymology Dictionary

TADPOLE,  a young frog in its first stage, having a tail.  (Hybrid; E. and C.)   'Young frogs,... whiles they be tadpoles and have little wriggling tailes;' Holland, tr. of Pliny, b. xxxii. c. 10.   Called bullhead in Cotgrave; he has:  'Chabot, the little fish called a gull, bull-head, or miller's thumbe; also the little water-vermine called a bull-head.'   Also:  'Testard, the pollard, or chevin fish, also the little black water-vermine called a bull-head.'   Observe that F. chabot is from Lat. caput, a head (cf. Lat. capito, a fish with a large head); that testard is from O. F. teste, a head; that chevin is from F. chef, a head; and that bull-head contains the E. head; the striking feature about the tadpole is that it appears nearly all head, with a little tail attached which is body and tail in one.   See Wedgwood, who adduces also E. dial. poll-head, Lowl. Sc. pow-head, a tadpole (which merely repeat the notion of head), E. dial. polwiggle, pollywig, a tadpole, with which we may compare wiggle or waggle, to wag the tail.   β. Hence tad-pole = toad-poll, the toad that seems all poll; see Toad and Poll.   The former part of the word is E., the latter (ultimately) of Celtic origin.