H.d.

1.
(in prescriptions) at bedtime.
1.
heavy duty.
[doo-lit-l] /ˈduˌlɪt l/
noun
1.
Hilda (“H.D”) 1886–1961, U.S. poet.
2.
James Harold, 1896–1993, U.S. aviator and general.
/ˈduːlɪtəl/
noun
1.
Hilda. known as H.D. 1886–1961, US imagist poet and novelist, living in Europe

h.d. abbr.
Latin hora decubitus (before sleep, at bedtime)
Latin hora decubitus (at bedtime)