The Mafia: any particular mafia, mentioned uniquely within the discussion's established or implicit context, usually and especially the Sicilian–Italian–Italian-American one (especially in American English) but occasionally others (e.g., the Russian one, the Japanese one).

The masses, especially the 'great unwashed masses': the general population, or (yet more specifically) the rabble thereof, viewed as one mob of unruly, disorganized people predisposed to violence and malevolence.

A large or disorderly group of people; especially one bent on riotous or destructive action.

(collective noun) A group of animals such as horses or cattle.

(collective noun) A group of kangaroos.

(collective noun) A flock of emus.

A mafia: a group that engages in organized crime.

(video games) A non-player character, especially one that exists to be fought or killed to further the progression of the story or game.

(Australian Aboriginal) A group of Aboriginal people associated with an extended family group, clan group or wider community group, from a particular place or country.

A mob cap.

Abbreviation of mobile phone.

(transitive) To crowd around (someone), sometimes with hostility.

(transitive) To crowd into or around a place.

(transitive) To wrap up in, or cover with, a cowl.