wing vs wing case

wing and wing case both are nouns.

Word	Noun	Adjective	Verb	Adverb
wing	Yes	No	Yes	No
wing case	Yes	No	No	No

As nouns, wing case is a hyponym of wing; that is, wing case is a word with a more specific, narrower meaning than wing:

wing: a movable organ for flying (one of a pair)
wing case: either of the horny front wings in beetles and some other insects which cover and protect the functional hind wings

Other hyponyms of wing include ala, fore-wing, fore wing, forewing, balancer, halter, haltere, pennon, pinion, elytron.

wing (noun)	wing case (noun)
a movable organ for flying (one of a pair)	either of the horny front wings in beetles and some other insects which cover and protect the functional hind wings
one of the horizontal airfoils on either side of the fuselage of an airplane
an addition that extends a main building
a barrier that surrounds the wheels of a vehicle to block splashing water or mud
a stage area out of sight of the audience
the wing of a fowl
a unit of military aircraft
the side of military or naval formation
a group within a political party or legislature or other organization that holds distinct views or has a particular function
(in flight formation) a position to the side and just to the rear of another aircraft
a hockey player stationed in a forward position on either side

wing (verb)	wing case (verb)
travel through the air; be airborne