Intense (adjective)

1. Of extreme force, degree, or strength.
2. Having or showing strong feelings or opinions.
3. Having or showing strong concentration.

Origin:

From old french intense, from latin intensus ("stretched, strained, tight, intense"), from in- ("in") + tendere ("to stretch").

Examples:

1. The heat was intense.
2. She had an intense dislike for him.
3. He was intense in his concentration on the game.
4. The storm was intense and lasted for hours.
5. The debate was intense and heated.