Grammatical agreement within a clause of one element with another according to the meaning of the latter rather than its morphological form.
An example of synesis is the construction of a collective noun in the singular with the plural form of a verb, as in the sentence ‘the cast have been nominated for an award’ rather than ‘the cast has been nominated for an award’..
Origin
Early 18th century. From post-classical Latin synesis from ancient Greek σύνεσις (Attic ξύνεσις) understanding, intelligence, in medieval Greek also as a grammatical term from συνιέναι to understand + -σις.