Webster's Revised Unabridged Dictionary · 1913

Nauplius

Nauplius , noun

[Latin, a kind of shellfish, from Greek nay^s ship + {not transcribed} to sail.]

(Zoology) A crustacean larva having three pairs of locomotive organs (corresponding to the antennules, antennae, and mandibles), a median eye, and little or no segmentation of the body.