Pathology Abnormally sensitive to a stimulus.(adjective)
Physiology Capable of responding to stimuli.(adjective)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "irritable" in a sentence
"The song had ceased from his lips; but Mary was irritable from a burnt hand and a grandchild whose stomach refused to digest properly diluted cows 'milk."
"Anne Crank: Diary of a Young Girl - increasingly irritable from the combination of cabin fever and puberty, Anne begins to write bitter rants against those who share the attic with her."
"Yet people are quick to label irritable or angry people as “bad children” or “bad people.”"