adjective

1. occurring or existing in a high degree; very strong; violent, extreme, sharp, vivid, etc. an intense light
2. strained to the utmost; strenuous; earnest; fervent; zealous intense thought
3. having or showing strong emotion, firm purpose, great seriousness, etc. an intense person
4. characterized by much action, emotion, etc.

Etymology: ME < MFr < L intensus, pp. of intendere: see intend