Inchworm \Inch"worm`\, n. (Zool.)
The larva of any geometrid moth. It progresses forward by
first bringing the rear end of the body forward, forming a
loop, then moving the front part of the body; called also
{measuring} worm, {measuringworm}, {spanner}, and {looper}.
See {Geometrid}.
[1913 Webster]