Cyclic domain

In phonology and morphology, a cyclic domain is a term used for a morphologically complex string, consisting of a base and an affix, to which the whole set of cyclic phonological rules apply.

Example
In English the adjective opaque plus the nominal suffix -ity (formally represented as [[opaque] ity]) constitute a cyclic domain to which the cyclic stress rules and the cyclic rules of Trisyllabic Shortening and Velar Softening apply, yielding the surface form opácity.

Link
Utrecht Lexicon of Linguistics