hypothetical vs supposed

hypothetical is a noun but supposed is not a noun.

Word	Noun	Adjective	Verb	Adverb
hypothetical	Yes	Yes	No	No
supposed	No	Yes	No	No

As adjectives, hypothetical and supposed are synonyms defined as:

hypothetical and supposed: based primarily on surmise rather than adequate evidence

Other synonyms of hypothetical include conjectural, divinatory, hypothetic, suppositional, suppositious, supposititious.

hypothetical (noun)	supposed (noun)
a hypothetical possibility, circumstance, statement, proposal, situation, etc.

hypothetical (adjective)	supposed (adjective)
based primarily on surmise rather than adequate evidence	required or under orders
	doubtful or suspect
	based primarily on surmise rather than adequate evidence
	mistakenly believed