Meaning

• Causing vexation or annoyance; teasing; troublesome.

• Full of trouble or disquiet

• (of an action) Commenced for the purpose of giving trouble, without due cause.

  "a vexatious lawsuit"

• (of a party or entity) 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"