What does "mum" mean?

Mum: Silent; not speaking. Thackeray. The citizens are mum, and speak not a word. Shak.

Additional senses

  1. 2.Be silent! Hush! Mum, then, and no more. Shak.
  2. 3.Silence. [R.] Hudibras.
  3. 4.A sort of strong beer, originally made in Brunswick, Germany. Addison. The clamorous crowd is hushed with mugs of mum. Pope.

Sources