measuringworm

US: (mezh′ər ing wûrm′)

WordReference Random House Unabridged Dictionary of American English © 2026

meas•ur•ing•worm  (mezh′ər ing wûrm′), n. 

1. Insects the larva of any geometrid moth, which progresses by bringing the rear end of the body forward and then advancing the front end.

Also, meas′uring worm′. Also called inchworm, looper, spanworm. 

• measuring + worm 1835–45, American.

Collins Concise English Dictionary © HarperCollins Publishers::

measuring worm noun

1. the larva of a geometrid moth: it has legs on its front and rear segments only and moves in a series of loops
   Also called: looper, inchworm