Meaning

noun the aspect of a verb that expresses its duration

originFrom duration + -ive. Alternatively, borrowed from French duratif, from Old French duratif (“lasting continuously (for a certain time)”), via Anglo-Norman French, and existing in the form duratif from about the twelfth through the fourteenth centuries, when the spelling was altered to durative under the influence of the literary Neolatin movement. Analogous to dure (“to last, to continue”) + -ive.

Etymology from Wiktionary, CC BY-SA 3.0