What is the meaning of Fractionate?

To separate (a mixture) into its individual constituents by exploiting differences in some chemical or physical property, such as boiling point, particle size, solubility etc.

To divide a total dose of radiation into fractions.

To divide each plaintext symbol into several ciphertext symbols as a preliminary stage of encryption.

To use the technique of fractionation in hypnosis.

Source: wiktionary.org