The Deltived asteroid belt was an asteroid belt that was once misplaced by Q2.
In 2366, Q taunted Q2 with this fact when Q2 expressed his frustration at having to apologize for Q's actions everywhere he went. (TNG: "Deja Q")
This asteroid belt was only mentioned in dialogue."DEL-tih-ved" was the pronunciation for this asteroid belt's name from the script pronunciation guide. [1]