/ˌkarē-ōkəˈnēsis/
Noun
1. The process of change that takes place during the division of a cell nucleus at mitosis or meiosis.(wiktionary.org)
2. Organic process consisting of the division of the nucleus of a cell during mitosis or meiosis. (wordnetweb.princeton.edu)
3. Division of a cell nucleus during mitosis. (Google Dictionary)