cover vs shell

cover and shell both are nouns.

Word	Noun	Adjective	Verb	Adverb
cover	Yes	No	Yes	No
shell	Yes	No	Yes	No

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

cover (noun)	shell (noun)
the act of concealing the existence of something by obstructing the view of it	the hard largely calcareous covering of a mollusc or a brachiopod
fire that makes it difficult for the enemy to fire on your own individuals or formations	hard outer covering or case of certain organisms such as arthropods and turtles
a false identity and background (especially one created for an undercover agent)	ammunition consisting of a cylindrical metal casing containing an explosive charge and a projectile; fired from a large gun
a recording of a song that was first recorded or made popular by somebody else	a metal sheathing of uniform thickness (such as the shield attached to an artillery piece to protect the gunners)
bedding that keeps a person warm in bed	the housing or outer covering of something
a covering that serves to conceal or shelter something	a very light narrow racing boat
covering for a hole (especially a hole in the top of a container)	a rigid covering that envelops an object
the protective covering on the front, back, and spine of a book	the exterior covering of a bird's egg
a natural object that covers or envelops	the hard usually fibrous outer layer of some fruits especially nuts
a fixed charge by a restaurant or nightclub over and above the charge for food and drink	the material that forms the hard outer covering of many animals

cover (verb)	shell (verb)
sit on (eggs)	remove from its shell or outer covering
clothe, as if for protection from the elements	remove the husks from
protect by insurance	use explosives on
act on verbally or in some form of artistic expression	come out better in a competition, race, or conflict
be responsible for reporting the details of, as in journalism	hit the pitches of hard and regularly
maintain a check on; especially by patrolling	look for and collect shells by the seashore
protect or defend (a position in a game)	fall out of the pod or husk
hold within range of an aimed firearm	create by using explosives
play a higher card than the one previously played
be responsible for guarding an opponent in a game
provide with a covering or cause to be covered
form a cover over
copulate with a female, used especially of horses
cover as if with a shroud
put something on top of something else
travel across or pass over
hide from view or knowledge
spread over a surface to conceal or protect
be sufficient to meet, defray, or offset the charge or cost of
to take an action to protect against future problems
invest with a large or excessive amount of something
help out by taking someone's place and temporarily assuming his responsibilities
provide for
span an interval of distance, space or time
include in scope; include as part of something broader; have as one's sphere or territory
make up for shortcomings or a feeling of inferiority by exaggerating good qualities