Medical Definition of refractory
1: resistant to treatment or cure <a refractory fulminant lesion> <had disease that was extremely refractory to multiple intensive therapies—Michelle L. Bennett et al>
2: unresponsive to stimulus <the refractory period of a muscle fiber>
3: resistant or not responding to an infectious agent : immune <refractory to reinfection>
Seen and Heard
What made you want to look up refractory? Please tell us where you read or heard it (including the quote, if possible).