suppose vs speculate

suppose and speculate both are verbs.

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

As verbs, suppose and speculate are synonyms defined as:

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

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

As verbs, speculate is a hypernym of suppose; that is, speculate is a word with a broader meaning than suppose:

suppose: express a supposition
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 (verb)	speculate (verb)
expect, believe, or suppose	reflect deeply on a subject
to believe especially on uncertain or tentative grounds	to believe especially on uncertain or tentative grounds
require as a necessary antecedent or precondition	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
take for granted or as a given; suppose beforehand	invest at a risk
express a supposition