1921, transitive, "bid or force (someone) to silence with the "shhh" sound, imitative of the command to be quiet (1904), itself an expansion of sh. Related: Shushed; shushing.
Entries linking to shush
sh interj.
exclamation used to urge or request silence, 1847 (hush in this sense is from c. 1600). The gesture of putting a finger to the lips to express silence is attested from Roman times. As a transitive verb from 1887; intransitive from 1925.