Green’s Dictionary of Slang

sweetmouth adj.

[sweetmouth n.]
(W.I.)

1. flattering.

[WI] ‘Blackbird and Woss-Woss’ in W. Jekyll Jam. Song and Story 24: The fellow so sweet-mout’ say in cross way ‘No’.
[US]J. Peterkin Roll, Jordan, Roll 103: But Harry, e too sweet-mouth! [...] Harry talk so promisin.
[UK]T. Rhone Old Story Time 1 i: Sweet-mouth politician promise to bring down the moon.
[US]C. Cooper Female Sexuality in Lyrics of Bob Marley and Shabba Ranks 4: This is classic Jamaican sweet-mouth talk.

2. greedy, gluttonous.

[WI]V. Heaven Jam. Proverbs n.p.: Sweet-mout fly follow coffin go a hole [DJE].
[WI]W. Jekyll Jam. Song and Story 24: The fellow so sweet-mout’ [DJE].