To intensify means to become stronger, more extreme, or more powerful, or to make something that way. When a storm intensifies, the wind blows harder and the rain falls heavier. When you intensify your study habits before a big test, you focus more deeply and work longer hours.

Think about turning up the volume on a speaker: the sound intensifies. Or imagine a close basketball game where both teams really want to win. As the final minutes tick away, the competition intensifies because everyone plays harder and the pressure builds.

The word often appears when something that already exists grows more forceful or concentrated. A disagreement between friends might intensify into a real argument if neither person backs down. Scientists might intensify their search for a cure by adding more researchers and running more experiments. A coach might ask players to intensify their efforts during practice, meaning to push themselves harder than before.

Notice that intensify describes a change, not a starting point. You wouldn't say a whisper intensifies into normal speech. You'd say someone's voice intensified from normal speech into shouting. The word captures that moment when something goes from strong to stronger, from serious to more serious.