speculate vs suppose

speculate and suppose both are verbs.

Word	Noun	Adjective	Verb	Adverb
speculate	No	No	Yes	No
suppose	No	No	Yes	No

As verbs, speculate and suppose are synonyms defined as:

speculate and suppose: to believe especially on uncertain or tentative grounds

Other synonyms of speculate include conjecture, hypothecate, hypothesise, hypothesize, theorise, theorize.

As verbs, suppose is a hyponym of speculate; that is, suppose is a word with a more specific, narrower meaning than speculate:

speculate: talk over conjecturally, or review in an idle or casual way and with an element of doubt or without sufficient reason to reach a conclusion
suppose: express a supposition

Other hyponyms of speculate include guess, hazard, pretend, venture, say.

speculate (verb)	suppose (verb)
reflect deeply on a subject	expect, believe, or suppose
to believe especially on uncertain or tentative grounds	to believe especially on uncertain or tentative grounds
talk over conjecturally, or review in an idle or casual way and with an element of doubt or without sufficient reason to reach a conclusion	require as a necessary antecedent or precondition
invest at a risk	take for granted or as a given; suppose beforehand
	express a supposition