Definition of "irritability" []

• The quality or state of being irritable; testiness or petulance. (noun)
• Pathology Abnormal or excessive sensitivity of a body organ or part to a stimulus. (noun)
• Physiology The capacity to respond to stimuli. (noun)

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.

• "I am so tired I can hardly keep my eyes open, and the irritability is astounding."
• "They can include: difficulty breathing sweating while nursing or taking a bottle poor weight gain irritability, lethargy or unresponsiveness (the baby seems “out of it”)"
• "His irritability is so terrible upon politics that they are no sooner the topic of discourse than they cast upon his face the expression of a man who is going to defend himself against murderers!"