Webster's Revised Unabridged Dictionary · 1913

Epimeron

Epimeron , noun

[New Latin, from Greek 'epi` upon + {not transcribed} a part.]

(a)
(Zoology) In crustaceans: The part of the side of a somite external to the basal joint of each appendage.
(b)
(Zoology) In insects: The lateral piece behind the episternum.