Other forms: intensified, intensifying, intensifies
To intensify is to make something stronger or more extreme. Intensify the search, the storm intensified, intensify efforts.
It works both ways without changing form: you intensify a thing and a thing intensifies. In meteorology it is a technical term for a storm strengthening, measured by falling pressure. Note intense, intensity; and that the Latin means stretched tight, from tendere, to stretch.
1verbintensifyTo make something stronger or more extreme.
“The rain intensified, and soon the streets were flooded.”
intensify is a strengthening.
Intense plus -ify, from Latin intensus, stretched tight, from tendere. Tension and tend come from the same stretching.
Proto-Indo-European
*tend- — to extend, stretch
Latin
intēnsus — strained, stretched tight; intense; attentive; violent; (rare) eager, intent
Old French
intense
Middle English
intens
English
intense
English, today
intensify
Built from
From intense + ify. Compare French intensifier. intense comes from Late Middle English intens, intense (“ardent, fervent; extreme, great, intense”), borrowed from Old French intense (modern French intense), or directly from its etymon Latin intēnsus (“strained, stretched tight; intense; attentive; violent; (rare) eager, intent”), the perfect passive participle of intendō (“to stretch out, strain”), from in- + tendō (“to extend, stretch”) (ultimately from Proto-Indo-European tend- (“to extend, stretch”)).
Etymology from Wiktionary, CC BY-SA