Deadhead
A "dead head" is someone who doesn't pay. Originally, it probably referred to a train passenger who didn't pay for a ticket, but it soon included nonpaying "customers" at theatrical events as well.
"Dead head" is historical. "Dead beat" has much the same meaning today.
16 June 1840, Milwaukee (WI) Sentinel, pg. 2:
Ai'nt the liberties of our country in danger, when the gentleman of the Press can't go as "dead heads on the lake?"
23 January 1841, Spirit of the Times, pg. 564:
Niblo's Concerts. (...) The house on Tuesday was filled as far as $300 could fill it, barring "the dead heads;" a good proportion of the audience were ladies.
26 October 1841, Huron Reflector (Norwalk, Ohio), pg. 2:
Joshua A. Smith said he was on board the Caroline, was a "dead-head" passenger (one who did not pay, as the other witnesses were;) also that he heard a gun fired when he was at the gangway, and some one fell at his side.
"Dead head" is historical. "Dead beat" has much the same meaning today.
16 June 1840, Milwaukee (WI) Sentinel, pg. 2:
Ai'nt the liberties of our country in danger, when the gentleman of the Press can't go as "dead heads on the lake?"
23 January 1841, Spirit of the Times, pg. 564:
Niblo's Concerts. (...) The house on Tuesday was filled as far as $300 could fill it, barring "the dead heads;" a good proportion of the audience were ladies.
26 October 1841, Huron Reflector (Norwalk, Ohio), pg. 2:
Joshua A. Smith said he was on board the Caroline, was a "dead-head" passenger (one who did not pay, as the other witnesses were;) also that he heard a gun fired when he was at the gangway, and some one fell at his side.