1. (v.) To make sweet to the taste; as, to sweeten tea.

2. (v.) To make pleasing or grateful to the mind or feelings; as, to sweeten life; to sweeten friendship.

3. (v.) To make mild or kind; to soften; as, to sweeten the temper.

4. (v.) To make less painful or laborious; to relieve; as, to sweeten the cares of life.

5. (v.) To soften to the eye; to make delicate.

6. (v.) To make pure and salubrious by destroying noxious matter; as, to sweeten rooms or apartments that have been infected; to sweeten the air.

7. (v.) To make warm and fertile; -- opposed to sour; as, to dry and sweeten soils.

8. (v.) To restore to purity; to free from taint; as, to sweeten water, butter, or meat.

9. (v. i.) To become sweet.