Definition of "irritant" []

• Causing irritation, especially physical irritation. (adjective)
• A source of irritation: tobacco smoke, a common eye irritant. (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.

• "Another irritant is his mouthpiece daughter who spews the same nonsense her father does on every station possible."
• "After contact with a skin irritant plant, wash the exposed areas thoroughly with soap and water."
• "Respondents by a 2-to-1 margin said Beijing's efforts to address a key long-term irritant, intellectual-property theft, is stagnant at best."