These words refer to large gatherings, especially of people. Throng and host are the most formal of these. Throng emphasizes a group in which the members are pressed together in a crush: a throng of late Christmas shoppers fighting one another to the display tables of the department store. The word can suggest also a mass of tightly grouped people moving with difficulty in the same direction: a throng of worshippers who followed the religious procession down the narrow cobbled streets of the town. Host , by contrast, suggests an archaic or Biblical tone; here the group may well be spread out in space. The word may be descriptive of an army or armed group of people: the heavenly host of angels who appeared to the shepherds near Bethlehem; a host of people spread out on the hillside in all directions; a ragged host of guerrillas, falling before the gunfire of well-hidden government troops. The word can suggest also any vast group of things: a host of reasons for disbanding the cavalry.

Crowd and mob both suggest sizeable collections of people, but both are more informal than the previous pair. Like throng , crowd can suggest congestion but is even more emphatic about disorder within the group: a confused crowd that gathered in the street to watch the burning house. The word is used informally to describe large audiences of any kind, even the most orderly: the large crowd that had turned out to hear the pianist’s farewell performance. Mob , by contrast, stresses disorder in a crowd possessed by unruly or angry emotions and implies the erupting of potential violence or a state of riot: a crowd that turned into a rampaging mob when it learned that the boy injured by the hit-and-run driver had died before reaching the hospital. As a mere hyperbole, the word can be used informally for any great number: mobs of friends who came to our house-warming party.

Multitude , while not sharing the quaint or old-fashioned sound of host , gives an elevated tone in referring to an extremely large number; when the word applies to people, it specifically implies their being spread out through space: the multitude gathered in King’s Cross to see in the New Year. Like host , the word can apply also to any great amount: presenting a multitude of reasons for reopening the case. Horde refers specifically to a crowd or mob that is threatening, unkempt or unpleasant in some way: a horde of hungry peasants who gathered before the palace. In this context, the word suggests disorganization, fierce emotion and a motley or ragged array of people. Horde can refer also to a pack or swarm, as of animals or insects: a horde of moths that circled the night light; a horde of rats. Most specifically, and with a less negative tone, the word can refer to a nomadic tribe or army: the horde of Bedouins who camped for the night just outside the desert town.