Synesis


Synesis is a traditional grammatical/rhetorical term derived from Greek σύνεσις.
A constructio kata synesin is a grammatical construction in which a word takes the gender or number not of the word with which it should regularly agree, but of some other word implied in that word. It is effectively an agreement of words with the sense, instead of the morphosyntactic form.
Examples:
Here, the plural pronoun they and the plural verb form are co-refer with the singular noun band. One can think of the antecedent of they as an implied plural noun such as musicians.
Such use in English grammar is often called notional agreement, because the agreement is with the notion of what the noun means, rather than the strict grammatical form of the noun. The term situational agreement is also found, since the same word may take a singular or plural verb depending on the interpretation and intended emphasis of the speaker or writer:
Other examples of notional agreement for collective nouns involve some uses of the words team and none.
Although notional agreement is more commonly used in British English than in American English, some amount is natural in any variety of English. American style guides give advice, for example, on notional agreement for phrases such as a number of, a lot of, and a total of. The AMA Manual of Style says, "The number is singular and a number of is plural" and "The same is true for the total and a total of". This is the same concept that is covered by Chicago style at "5.9 Mass noun followed by a prepositional phrase", but not all of the relevant nouns are mass nouns.