vexatious

vexatious \vek-SEY-shuhs\, adjective:

1. causing vexation; troublesome; annoying: a vexatious situation.
2. Law. (of legal actions) instituted without sufficient grounds and serving only to cause annoyance to the defendant.
3. disorderly; confused; troubled.

The courts of law would never be so constantly crowded with petty, vexatious and disgraceful suits, were it not for the herds of pettifogging lawyers that infest them.
-- Washington Irving, A History of New York, 1809

Thus the most vexatious and violent disputes would often arise between the fishermen, were there not some written or unwritten, universal, undisputed law applicable to all cases.
-- Herman Melville, Moby Dick; or, The Whale, 1851

Vexatious entered English from the Latin word vexāre which meant "to shake, jolt, harass, annoy."