vexatious

Etymology

a 1650 vexation + -ous

adj

1. Causing vexation or annoyance; teasing; troublesome.
2. (archaic) Full of trouble or disquiet
   He leads a vexatious life. 1644, Kenelm Digby, Two Treatises, To My Son Kenelm Digby (preface)
3. (law, of an action) Commenced for the purpose of giving trouble, without due cause.
   a vexatious lawsuit
4. (law, 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