1.NounA 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.
"Methane is separated from other hydrocarbons in a gas fractionation plant.; After several fractionations, we had a usable product."
2.NounThe division of a total dose of radiation into fractions.
3.NounA preliminary stage of encryption that divides each plaintext symbol into several ciphertext symbols.
4.NounA form of hypnosis where the patient is made to enter and leave a trance state many times in quick succession.