The unclued lights (two of two words) are of a kind, verifiable in Brewer among other reference books. Elsewhere, ignore one grave accent.

Across

1    Complete support for defender (8)
6    Wan painting child’s vehicle (6)
11    Novice leads the experts, then ties (5)
14    Calm meeting in silence (6)
16    Slight, and slightly less than yours (4)
17    Correct object kept by English chum (8)
21    Subjugated Russian perhaps, trapped in valley in revolution (8)
25    A tip given in the olden days (3)
26    Pheasant’s nest is close by, reportedly (3)
28    Billy’s relatives are child-minders (7)
29    Computer test on gag on sport (8, hyphened)
34    Husband en route to...