Crowd, throng, press, crush, mob, rout, horde are comparable when they mean a more or less closely assembled multitude usually of persons.
Crowd basically implies a close gathering and pressing together. It often implies a merging of the individuality of the units into that of the mass.
Throng varies so little in meaning from crowd that the two words are often used interchangeably without loss. Throng sometimes carries the stronger implication of movement and of pushing and the weaker implication of density.
Press differs from throng in being more often applied to a concentrated mass in which movement is difficult because of the numbers, but otherwise it also suggests pushing or pressing forward.
Crush carries a stronger implication than either crowd or throng of compactness of the group, of offering difficulty to one who wishes to make his way through it, or of causing discomfort to one who is part of it.
Mob strictly applies to a crowd or throng bent on the accomplishment of riotous or destructive acts.
Especially in the United States and in Australia mob may be employed as an intensive of crowd, sometimes implying more disorganization, but at other times denoting merely an extremely large crowd.
In theatrical use mob applies to any large and manifestly agitated crowd of persons that has to be directed as a unit to achieve the proper or the intended effects.
Rout applies to an especially disorderly or tumultuous mob.
Horde usually applies to an assemblage or to a multitude massed together. It is sometimes preferred to crowd, throng, mob, or rout when a contemptuous term is desired, especially one that suggests the rude, rough, or savage character of the individuals who constitute the multitude or mass.