Real Dictionary

eggshell
Eggshell paint makes surfaces dull, not shiny, when it is painted on them.
variable noun: An eggshell is the hard covering on the outside of an egg.

eggshell in American English
fragile and thin, like eggshell
the hard, brittle outer covering of an egg of a reptile, bird, or monotreme
adjective: like an eggshell, as in thinness and delicacy; very brittle; fragile
noun: the shell of a bird's egg, consisting of keratin fibers and calcite crystals

eggshell in British English
noun: the hard porous protective outer layer of a bird's egg, consisting of calcite and protein