vex

Short definition from Wiktionary

Verb

1. 1
   To annoy, irritate.
2. 2
   To cause (mental) suffering to; to distress.
3. 3
   To trouble aggressively, to harass.
4. 4
   To twist, to weave.
5. 5
   To be irritated; to fret.
6. 6
   To toss back and forth; to agitate; to disquiet.

Noun

1. 1
   A trouble.

Proper noun

1. 1
   Initialism of Venus Express.