(transitive) To make sweet to the taste.to sweeten tea
(transitive) To make pleasing or grateful to the mind or feelings.to sweeten lifeto sweeten friendship
(transitive) To make mild or kind; to soften.to sweeten the temper
(transitive) To make less painful or laborious; to relieve.to sweeten the cares of life
unknown dateJohn Keble:And sweeten every secret tear.
(transitive) To soften to the eye; to make delicate.
unknown dateJohn Dryden:Correggio has made his memory immortal by the strength he has given to his figures, and by sweetening his lights and shadows, and melting them into each other.
(transitive) To make pure and salubrious by destroying noxious matter.to sweeten rooms or apartments that have been infectedto sweeten the air
(transitive) To make warm and fertile.to dry and sweeten soils
(transitive) To restore to purity; to free from taint.to sweeten water, butter, or meat
(transitive) To make more attractive; said of offers in negotiations.to sweeten the deal by increasing the price offered