In linguistics, incorporation is a phenomenon by which a grammatical category, such as a verb, forms a compound with its direct object (object incorporation) or adverbial modifier, while retaining its original syntactic function. The inclusion of a noun qualifies the verb, narrowing its scope rather than making reference to a specific entity.

Incorporation is central to many polysynthetic languages such as those found in North America, Siberia and northern Australia. However, polysynthesis does not necessarily imply incorporation (Mithun 2009), and the presence of incorporation does not imply that the language is polysynthetic.

Although incorporation does not occur regularly, English uses it sometimes: breastfeed, and direct object incorporation, as in babysit. Etymologically, such verbs in English are usually back-formations: the verbs breastfeed and babysit are formed from the adjective breast-fed and the noun babysitter respectively. Incorporation and plain compounding may be fuzzy categories: consider backstabbing, name-calling, axe murder.

The following example from Oneida (Iroquoian) illustrates noun incorporation.

waʼ-

FACT-

k-

1.SG-