WordNet sense 1 (the exterior covering of a bird's egg):

eggshell

WordNet sense 2 (a very light narrow racing boat):

racing shell

WordNet sense 3 (the housing or outer covering of something):

case, casing, case

WordNet sense 4 (a metal sheathing of uniform thickness (such as the shield attached to an artillery piece to protect the gunners)):

plate, scale

WordNet sense 5 (hard outer covering or case of certain organisms such as arthropods and turtles):

carapace, cuticle, shield

WordNet sense 6 (use explosives on):

blast

WordNet sense 7 (come out better in a competition, race, or conflict):

beat, crush, trounce, vanquish, beat out

WordNet sense 8 (remove the husks from):

husk