idiomaticity

Meanings

1. The quality of being idiomatic.
2. An instance or category of instances of that quality.
3. The state of a linguistic expression which exists when the expression exhibits semantic-pragmatic divergence, when the semantic value of the expression differs from its pragmatic value; that is to say, idiomaticity exists when the inherent meaning of the words expressed does not match the meaning of the expression as understood by the users: the sayer(s) and hearer(s).

Etymology

From idiomatic + -ity.