common man vs secular

common man and secular both are nouns.

Word	Noun	Adjective	Verb	Adverb
common man	Yes	No	No	No
secular	Yes	Yes	No	No

As nouns, secular is a hyponym of common man; that is, secular is a word with a more specific, narrower meaning than common man:

common man (noun)	secular (noun)
a person who holds no title	someone who is not a clergyman or a professional person

common man (adjective)	secular (adjective)
	of or relating to clergy not bound by monastic vows
	not concerned with or devoted to religion
	characteristic of or devoted to the temporal world as opposed to the spiritual world
	of or relating to the doctrine that rejects religion and religious considerations
	characteristic of those who are not members of the clergy