1. causing or characterized by a headache; tending to produce a headache
Usage: informal; commonly used in everyday speech
2. annoying, frustrating, or troublesome; difficult to deal with
Usage: informal; figurative use

Examples

• That bright fluorescent lighting is really headachey.
• The constant noise from construction is giving me a headachey feeling.
• Dealing with the insurance company has been a headachey process.
• Too much screen time makes me feel headachey by the end of the day.
• The project turned out to be more headachey than we expected.