Webster's Revised Unabridged Dictionary · 1913

Proleg

Proleg , noun

[Prefix pro- for, in place of + leg.]

(Zoology) One of the fleshy legs found on the abdominal segments of the larva of Lepidoptera, sawflies, and some other insects. Those of Lepidoptera have a circle of hooks. Called also proped, propleg, and falseleg.