turba

Turba, turbae is first declension feminine, taken from Greek turbe. It carries two senses that lean on each other: the crowd itself, and the disorder a crowd produces. So turba can be a throng or a riot, and only the sentence decides.

That is why it is not the neutral word for a lot of people. Multitudo is the count, populus is the people as a body, vulgus is the common sort with a sneer attached, and turba is chosen when a writer wants the noise, the pushing and the risk. The verb turbo, turbare, "to stir up, throw into confusion", belongs with it, along with turbidus and perturbo. English inherits turbid, turbulent, disturb, perturb and, through Vulgar Latin turbulare, plain trouble.