title-holder vs champ

title-holder and champ both are nouns.

Word	Noun	Adjective	Verb	Adverb
title-holder	Yes	No	No	No
champ	Yes	No	Yes	No

As nouns, title-holder and champ are synonyms defined as:

title-holder and champ: someone who has won first place in a competition

Other synonyms of title-holder include champion.

title-holder (noun)	champ (noun)
someone who has won first place in a competition	someone who has won first place in a competition

title-holder (verb)	champ (verb)
	chew noisily or vigorously
	chafe at the bit, like horses