The story
- Proto-Indo-European · derived from*tend-“to extend, stretch”
- Latin · derived fromintēnsus“attentive; eager, intent; intensive”
- Medieval Latin · derived fromintēnsīvus
- Old French · derived fromintensif
- Middle English · inherited fromintensive“fervent, great, intense”
- English todayintensive
The adjective is derived from Late Middle English intensive (“fervent, great, intense”), borrowed from Old French intensif, intensive (modern French intensif) + Middle English -ive (suffix meaning ‘of the nature of, relating to’ forming adjectives), equivalent to intense + -ive. Intensif is from Medieval Latin intēnsīvus, from Latin intēnsus (“attentive; eager, intent; intensive”) + -īvus (suffix forming adjectives with the sense ‘doing; related to doing’); and intēnsus is the perfect passive participle of intendō (“to stretch out, strain”), from in- (prefix meaning ‘to, towards’) + tendō (“to extend, stretch, stretch out”) (ultimately from Proto-Indo-European *tend- (“to extend, stretch”)). Doublet of intend. The noun is derived from the adjective.
Words from the same roots
Etymology from Wiktionary, CC BY-SA 4.0.