An example of something vexatious is a computer that won't stop beeping in the office.
- characterized by or causing vexation; annoying, troublesome, etc.
- Law instituted without real grounds, chiefly to cause annoyance to the defendant: said of legal actions
(comparative more vexatious, superlative most vexatious)
a 1650 vexation +"Ž -ous