1. [adj]  not leased to or occupied by a tenant; "an unoccupied apartment"; "very little unclaimed and untenanted land"
2. [adj]  not held or filled or in use; "an unoccupied telephone booth"; "unoccupied hours"
3. [adj]  not seized and controlled; "unoccupied areas of France"

UNOCCUPIED is a 10 letter word that starts with U.