What is the meaning of Fractionation?

A separation process in which a certain quantity of a mixture is divided up into smaller quantities (fractions) in which the composition changes according to a gradient; an instance of this process.

The division of a total dose of radiation into fractions.

A preliminary stage of encryption that divides each plaintext symbol into several ciphertext symbols.

A form of hypnosis where the patient is made to enter and leave a trance state many times in quick succession.

Source: wiktionary.org