bio-break UK /ˈbaɪəʊˌbɹeɪk/US /ˈbaɪoʊˌbɹeɪk/ noun1 •(informal, euphemistic) A collective visit to a bathroom or restroom or stop to relieve oneself, especially during an established time or break in a group event.We stopped once for a bio-break at a road side gas station. Most of us (including a few women) used the bushes because it took too long to get in the bathrooms. — 2004 formsbio breaks · bio-breaks