(geometry) Initialism of side side angle (a geometric proof reason) / (engineering) Initialism of specific surface area. / (management) Initialism of supervisory special agent.

(historical) Initialism of Soviet Socialist Republic. / (aviation) Initialism of secondary surveillance radar. / (electronics) Initialism of solid-state relay.

(computing, of a diskette) Initialism of single-sided, double density.

Initialism of same shit, different day.

(onomatopoeia) The hiss of a snake or other reptile.

(electronics, communication) Initialism of single sideband, a type of radio emission. / Initialism of social security board.

(video games) Initialism of Super Smash Brothers. / (linguistics) Initialism of Standard Southern British.

(Philippines) Social Security System / (US) Selective Service System

(astronomy) Initialism of super soft source. / (medicine) Initialism of sick sinus syndrome. / (medicine) Initialism of subclavian steal syndrome. / (slang) Initialism of shit, shower, shave.

Be quiet or reduce the volume.