The Collaborative International Dictionary of English v.0.48:
Pupa \Pu"pa\, n.; pl. L. Pup[ae], E. Pupas. [L. pupa girl.
doll, puppet, fem. of pupus. Cf. Puppet.]
1. (Zool.) Any insect in that stage of its metamorphosis
which usually immediately precedes the adult, or imago,
Note: Among insects belonging to the higher orders, as the
Hymenoptera, Diptera, Lepidoptera, the pupa is inactive
and takes no food; in the lower orders it is active and
takes food, and differs little from the imago except in
the rudimentary state of the sexual organs, and of the
wings in those that have wings when adult. The term
pupa is sometimes applied to other invertebrates in
analogous stages of development.
2. (Zool.) A genus of air-breathing land snails having an
elongated spiral shell.
Coarctate pupa, or Obtected pupa, a pupa which is incased
in the dried-up skin of the larva, as in many Diptera.
Masked pupa, a pupa whose limbs are bound down and partly
concealed by a chitinous covering, as in Lepidoptera.