doornail

n (idm 习语) dead as a doornail => dead.

donkey-work, donnish, donor, doodle, doom, doomed, doomsday, door, door-bell, door-frame, door-handle, door-keeper, door-knob, door-knocker, door-plate, door-way, doorbell, doorknob, doorman, doormat, doorpost, doorstep, doorstop, doorway, dope, dopey (also dopy), Doric, dorm, dormancy, dormant, dormer, dormitory, dormitory town, dormouse, dorsal, dory, DOS, dosage, dose, doss,