Meaning of synesis

syn•e•sis

Pronunciation: (sin'u-sis), [key]
— n. Gram.
  1. a construction in which an expected grammatical agreement in form is replaced by an agreement in meaning, as in The crowd rose to their feet, where a plural pronoun is used to refer to a singular noun.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.