vexatious

adj

1. Causing vexation or annoyance; teasing; troublesome.

   “Although this letter is vexatious, I must not forget that my little entertainment has brought me a visiter in the Marquess of Wentworthdale, on an errand of no small moment, as the Countess of Rotheles may soon learn, to her surprise, for I shall, probably, see him at the Opera to-night.”

2. (archaic)Full of trouble or disquiet

   “He leads a vexatious life.”

3. Commenced for the purpose of giving trouble, without due cause.

   “a vexatious lawsuit”

4. In the habit of starting vexatious litigation and therefore liable to have restraints placed on one's ability to access the courts.

   “a vexatious litigant”