early 15c., from Mwdieval Latin assumptivus, from assumpt-, past participle stem of assumere/adsumere "take up, take to oneself" (see assume) + -ive. Oldest sense in English is medical, of bloodletting, "withdrawing humours from opposite parts of the body."
an assumptive person
assumptive beliefs
assuasive
assumable
assume
assumpsit
assumption
assumptive
assurance
assure
assured
Assyria
Assyriology