from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. Incapable of being stimulated to action, as a muscle.
from the GNU version of the Collaborative International Dictionary of English
- adj. Not irritable; esp. (Physiol.), incapable of being stimulated to action, as a muscle.
from The Century Dictionary and Cyclopedia
- Not irritable; good-natured; in physiology, not reacting to stimulation.
in- + irritable (Wiktionary)