[silence gives consent] If you say nothing or do not say […]

[silent majority] {n.}, {informal} The large majority of people who, unlike […]

[silver] See: [BORN WITH A SILVER SPOON IN ONE'S MOUTH], [EVERY […]

[silver anniversary] or [wedding] {n. phr.} The twenty-fifth wedding anniversary of […]

[simmer down] {v.}, {informal} To become less angry or excited; become […]

[Simon Legree] {n.}, {informal} A strict person, especially a boss, who […]

[simple] See: [PURE AND SIMPLE].

[sing a different tune] or [whistle a different tune] also [sing […]

[sing for one's supper] {v. phr.}, {informal} To have to work […]

[sing in tune] See: [IN TUNE].