Unclued lights give the names (one of two words) of some members of a distinguished group. A further member is the answer to a clued light and should be highlighted. One name does double duty.

Across

1    Enclose wife in vaulted chamber (8)

5    Mean times approaching (6)

14    Hard ball of wood found in manure (3)

16    In entrance a special delivery (6)

17    Military unit about to kill old man (5)

18    Knowledge of enemy movements occupying hill (5)

20    One applauding cook almost before end of dinner (7)

22    Concerned with bureau avoiding a period style (7)

24    Inability to decide about liar, given tip-offs (7)

25    Small...