Available Definitions:
1) a. - To make sweet to the taste; as, to sweeten tea.
2) a. - To make pleasing or grateful to the mind or feelings; as, to sweeten life; to sweeten friendship.
3) a. - To make mild or kind; to soften; as, to sweeten the temper.
4) a. - To make less painful or laborious; to relieve; as, to sweeten the cares of life.
5) a. - To soften to the eye; to make delicate.
6) a. - To make pure and salubrious by destroying noxious matter; as, to sweeten rooms or apartments that have been infected; to sweeten the air.
7) a. - To make warm and fertile; -- opposed to sour; as, to dry and sweeten soils.
8) a. - To restore to purity; to free from taint; as, to sweeten water, butter, or meat.
9) v. i. - To become sweet.