caller vs leader

caller and leader both are nouns.

Word	Noun	Adjective	Verb	Adverb
caller	Yes	Yes	No	No
leader	Yes	No	No	No

As nouns, leader is a hypernym of caller; that is, leader is a word with a broader meaning than caller:

caller (noun)	leader (noun)
a social or business visitor	a featured article of merchandise sold at a loss in order to draw customers
the person initiating a telephone call	a person who rules or guides or inspires others
the person who convenes a meeting
someone who proclaims or summons in a loud voice
a person who announces the changes of steps during a dance
the bettor in a card game who matches the bet and calls for a show of hands
an investor who buys a call option

caller (adjective)	leader (adjective)
providing coolness
fresh