OXFORD DICTIONARY
Gudgeon, n.
1 a small European freshwater fish, Gobio gobio, often used as bait.
2 a credulous or easily fooled person.
Gudgeon, n.
1 any of various kinds of pivot working a wheel, bell, etc.
2 the tubular part of a hinge into which the pin fits to effect the joint.
3 a socket at the stern of a boat, into which a rudder is fitted.
4 a pin holding two blocks of stone etc. together.
gudgeon-pin (in an internal-combustion engine) a pin holding a piston-rod and a connecting-rod together.
ME f. OF goujon dimin. of gouge GOUGE
THESAURUS
Gudgeon
arbor, axis, axle, axle bar, axle shaft, axle spindle, axle-tree, babe, boob, chump, cinch, credulous person, cull, distaff, dupe, easy mark, easy pickings, fall guy, fish, fool, fulcrum, gimbal, gobe-mouches, greener, greenhorn, greeny, gull, hinge, hingle, hub, innocent, leadpipe cinch, mandrel, monkey, nave, oarlock, patsy, pigeon, pin, pintle, pivot, plaything, pole, prize sap, pushover, radiant, rowlock, sap, saphead, schlemiel, sitting duck, spindle, stooge, sucker, swivel, toy, trunnion, trusting soul, victim
ROGET THESAURUS
Gudgeon
Dupe
N
dupe, gull, gudgeon, gobemouche, cull, cully, victim, pigeon, April fool, jay, sucker, laughingstock, Cyclops, simple Simon, flat, greenhorn, fool, puppet, cat's paw, credulous, mistaken.