secularism vs philosophy

secularism and philosophy both are nouns.

Word	Noun	Adjective	Verb	Adverb
secularism	Yes	No	No	No
philosophy	Yes	No	No	No

As nouns, philosophy is a hypernym of secularism; that is, philosophy is a word with a broader meaning than secularism:

secularism: a doctrine that rejects religion and religious considerations
philosophy: a belief (or system of beliefs) accepted as authoritative by some group or school

Other hypernyms of secularism include doctrine, ism, philosophical system, school of thought.

secularism (noun)	philosophy (noun)
a doctrine that rejects religion and religious considerations	the rational investigation of questions about existence and knowledge and ethics
	a belief (or system of beliefs) accepted as authoritative by some group or school
	any personal belief about how to live or how to deal with a situation