by 1974 in sense of "devotee of the rock music band the Grateful Dead;" earlier (with lower-case) "one who rides for free on the railroads" (1866), and "non-paying spectator" (1841).
the deadheads on the payroll should be eased out as fast as possible
dead reckoning
Dead Sea
deadbeat
dead-center
deaden
Deadhead
dead-lift
deadline
deadlock
deadly
dead-march
