'Soft-shelled crab' definitions:

Definition of 'soft-shelled crab'

noun

Freshly molted crab with new shell still tender and flexible [syn: soft-shell crab, soft-shelled crab]

noun

Edible crab that has recently molted and not yet formed its new shell [syn: soft-shell crab, soft-shelled crab]

From: GCIDE

Soft-shell \Soft"-shell`\, Soft-shelled \Soft"-shelled`\, a. Having a soft or fragile shell. [1913 Webster]
Soft-shell clam (Zool.), the long clam. See Mya.
Soft-shelled crab. (Zool.) See the Note under Crab, 1.
Soft-shelled turtle. (Zool.) Same as Soft tortoise, under Soft. [1913 Webster]