fisheyeDefinition of fisheye noun 1 (also fisheye lens) a very wide-angle lens with a field of vision covering up to 180°, the scale being reduced towards the edges. 2US informal a suspicious or unfriendly look:Wally gave him the fisheye 3a defect in metal causing a spot to stand out brightly against its surroundings. fisheye in other Oxford dictionaries Definition of fisheye in the US English dictionary