spanworm

noun

In entomology, a looper, measurer, or measuring-worm; the Iarva of any geometrid moth. See measuring-worm, inchworm, looper, loopworm, and especially geometer, 3. See cuts under cankerworm and Cidaria.

noun

The larva of any geometrid moth, as the cankerworm; a geometer; a measuring worm.

noun

A measuring worm.