preoccupied

adjective4

1. •
   Concerned with something else; distracted; giving one's attention elsewhere.

   • I was preoccupied with a deadline at work, and I forgot his birthday.
2. •
   Describing a taxonomic name not available for use because it is already used for another.

   • In 1924 J. D. Tothill revised the nearctic species in the genus Fabriciella, a name proposed by Bezzi in 1906 to replace Fabricia Rob. D. which is preoccupied. — 1931
3. •
   (no longer used) Already occupied.

   • Terrified at this uproar, which disconcerted the magician himself, she ran for shelter into the place which was preoccupied by the other lady […]. — 1751
4. •
   (no longer used) Prepossessed; biased.