Definition of "sweeten"
sweeten
/ˈswiːtən/
verb
third-person singular simple present sweetens, present participle sweetening, simple past and past participle sweetened
(transitive) To make pure and salubrious by destroying noxious matter.
(transitive) To make more attractive; said of offers in negotiations.
(music, transitive) To supplement (a composition) with additional instruments, especially strings.