Source : Webster's Revised Unabridged Dictionary (1913)

Subimago \Sub`i*ma"go\, n. [NL. See {Sub-}, and {Imago}.]
   (Zo["o]l.)
   A stage in the development of certain insects, such as the
   May flies, intermediate between the pupa and imago. In this
   stage, the insect is able to fly, but subsequently sheds a
   skin before becoming mature. Called also {pseudimago}.