measuringworm

or meas·ur·ing worm

[mezh-er-ing-wurm]
noun
  1. the larva of any geometrid moth, which progresses by bringing the rear end of the body forward and then advancing the front end.

Origin of measuringworm

An Americanism dating back to 1835–45; measuring + worm
Also called inchworm, looper, spanworm.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018