SSS

Social Security System.

Proper noun

  1. Social Security System.
  2. Selective Service System.

Noun

  1. Initialism of super soft source.
  2. Initialism of sick sinus syndrome.
  3. Initialism of subclavian steal syndrome.
  4. Initialism of shit, shower, shave.
  5. Initialism of subsurface scattering.