D is for

debonair
adjective

confident, stylish, and charming (typically used of a man).
"all the men looked debonair and handsome in white tie and tails"

decolletage
noun

a low neckline on a woman's dress or top.
a woman's cleavage as revealed by a low neckline on a dress or top.

diktat
noun

an order or decree imposed by someone in power without popular consent.
"a diktat from the Bundestag"

Definitions from Oxford Languages