larva(n = noun.animal) - the immature free-living form of most invertebrates and amphibians and fish which at hatching from the egg is fundamentally unlike its parent and must metamorphose;
is a kind of animal, animate being, beast, brute, creature, fauna
has particulars: ascidian tadpole, bladder worm, cercaria, wireworm, mealworm, wiggler, wriggler, jointworm, strawworm, ant lion, antlion, doodlebug, aphid lion, aphis lion, dobson, hellgrammiate, caseworm, caterpillar, nymph, leptocephalus, bot, grub, polliwog, pollywog, tadpole
Derived forms adjective larval₁, adjective larval₂

1.  Any young insect from the time that it hatches from the egg until it becomes a pupa, or chrysalis. During this time it usually molts several times, and may change its form or color each time. The larvæ of many insects are much like the adults in form and habits, but have no trace of wings, the rudimentary wings appearing only in the pupa stage. In other groups of insects the larvæ are totally unlike the parents in structure and habits, and are called caterpillars, grubs, maggots, etc. [1913 Webster]

2.  The early, immature form of any animal when more or less of a metamorphosis takes place, before the assumption of the mature shape. [1913 Webster]

larva, n. (pl. larvae)
1 the stage of development of an insect between egg and pupa, e.g. a caterpillar.
2 an immature form of other animals that undergo some metamorphosis, e.g. a tadpole.

Derivative:
larval adj. larvicide n.

Etymology:
L, = ghost, mask

N  infant, babe, baby, babe in arms, nurseling, suckling, yearling, weanling, papoose, bambino, kid, vagitus, child, bairn, little one, brat, chit, pickaninny, urchin, bantling, bratling, elf, youth, boy, lad, stripling, youngster, youngun, younker, callant, whipster, whippersnapper, whiffet, schoolboy, hobbledehoy, hopeful, cadet, minor, master, scion, sap, seedling, tendril, olive branch, nestling, chicken, larva, chrysalis, tadpole, whelp, cub, pullet, fry, callow, codlin, codling, foetus, calf, colt, pup, foal, kitten, lamb, lambkin, aurelia, caterpillar, cocoon, nymph, nympha, orphan, pupa, staddle, girl, lass, lassie, wench, miss, damsel, demoiselle, maid, maiden, virgin, hoyden, infantine, infantile, puerile, boyish, girlish, childish, babyish, kittenish, baby, newborn, unfledged, new-fledged, callow, in the cradle, in swaddling clothes, in long clothes, in arms, in leading strings, at the breast, in one's teens.

loeven's larva