Multitude

As we can guess easily, multitude comes from ‘multi’. The same ‘multi-‘ appears in a number of words, with the most common being multiply. That is exactly what this prefix does: it multiplies in numbers.

Multitude refers to the state of being huge or great in numbers. It can also be used to refer to collective populations, for example: India consists of vast and never ending multitudes.

Just a look at some multi-words:

Meanings of the words above:

Multipartite: Involving more than two parties
Multifold: Many times doubled; manifold; numerous
Multilingual: Using or knowing more than one language
Multitasking: Perform more than one task at the same time; originally of computers, now also more generally
Multilateral: Having many parts or sides

The dictionary definitions for Multitude are as follows:
1. The condition or quality of being numerous. (noun)
2. A very great number. (noun)
3. The masses; the populace: the concerns of the multitude. (noun)

PLEASE NOTE:
The following is an extract from The Hindu used for educational purposes: ‘Turks in their millions headed for the polls on June 12 to participate in a crucial parliamentary election which is likely to have a strong bearing on not only the country’s immediate future but also on millions outside, who are in the midst of an “Arab Spring.” Capturing the spirit of a series of bold pro-democracy uprisings in West Asia and North Africa, the Arab Spring promises to liberate vast multitudes in the region — from a stifling era of authoritarian rule.’
Read further on:
http://www.thehindu.com/opinion/lead/article2104555.ece