sinful, a. iniquitous, [wrong], [immoral], [wicked], depraved, [vicious], [unrighteous].
sinfulness, n. iniquity, [immorality], depravity, [wickedness].
sing, v. carol, [warble], [chant], hymn, [hum], troll, yodel, croon.
singe, v. sweal, swale, [scorch].
singer, n. vocalist, songster, songstress, [minstrel], chanter, cantatrice, cantor, prima donna, precentor, bard, troubadour, jongleur, musician.
single, a. individual, [alone], [particular], [isolated], [sporadic], [solitary]; [unmarried], celibate; [simple], unmixed; [honest], [sincere], ingenuous, [frank].
single, v. single [out], [choose], [select], [separate], [isolate], segregate.
single-hearted, a. [sincere], [honest], [guileless].
single-minded, a. [artless], [undesigning], [guileless].
singsong, n. monotone.--a. [monotonous], drawling.