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.
According to the script
, Deltived was pronounced as "DEL-tih-ved".