In grammar, conjugation is the modification of a verb from its basic form. See grammatical conjugation.

In biology, conjugation is sexual reproduction involving interchange of DNA between cells, rather than their fusion. Various forms of conjugation exist in different groups, such as bacteria (see bacterial conjugation) and ciliates.

In mathematics, the term is used in two senses:

In organic chemistry, conjugation is the interaction between two carbon-carbon double bonds, lowering the overall energy of the molecule.

See also: conjugate