Dico (dict-um), I say; verdict, dictation, dictionary, indictment.
Dies, a day; diary, meridian.
Dignus, worthy; dignity, indignant.
Do (dat-um), I give; donor, add [= ad-do, I give to], data.
Doceo (doct-um), I teach; docile, doctor.
Dominus, a lord; dominant, dominion, dame.
Domus, a house; domicile, domestic.
Dormio, I sleep; dormitory, dormant.
Duco (duct-um), I lead; induct, education, duke, produce.
Duo, two; dual, duel, (double), duplex.