mob

Concise Oxford English Dictionary © 2008 Oxford University Press:
mob/mɒb/

▶noun

• 1 a disorderly or violent crowd.

  ■ Brit. informal a group of people.

  ■ (the mob) the ordinary people.

• 2 (the Mob) N. Amer. the Mafia.

• 3 Austral./NZ a flock or herd of animals.

▶verb (mobs, mobbing, mobbed) crowd round or into in an unruly way.

– derivatives
mobber noun.

– origin C17: abbrev. of archaic mobile, short for L. mobile vulgus ‘excitable crowd’.