past vs preterite

past and preterite both are nouns.

Word	Noun	Adjective	Verb	Adverb
past	Yes	Yes	No	Yes
preterite	Yes	No	No	No

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

Other hyponyms of past include preterit, past simple, simple past.

past (noun)	preterite (noun)
a verb tense that expresses actions or states in the past	a term formerly used to refer to the simple past tense
the time that has elapsed
a earlier period in someone's life (especially one that they have reason to keep secret)

past (adjective)	preterite (adjective)
earlier than the present time; no longer current
of a person who has held and relinquished a position or office

past (adverb)	preterite (adverb)
so as to pass a given point