Gambolier- a gambler. See J. E. Lighter, Historical Dictionary of American Slang, vol. 1.
Perhaps spelled 'gambalier' originally.
The word appears in a verse of the Gold Rush song, "Poker Jim."
Verse 7
There was a noter gambalier a living in our camp,
They called him Poker Jim, and, oh! he was an awful scamp;
He used to come and talk to her, while I tried to make a strike,
And said she was a fool to love such an ugly d----d d----d Pike.

This song was first published in 1858 in Johnson, J. E., "Johnson's New Comic Songs, no. 2," San Francisco, D. E. Appleton & Co. (words and music, The Raging Canal, in Dwyer and Lingenfelter, "Songs of the Gold Rush," pp. 58-59).

"Night Side of New York," 1866- "The gay gamboliers would sometimes set four and twenty hours at a stretch."

1867, the magazine "Galaxy "(Nov.)- "A gay young gambolier stabs himself with the queen of hearts."

Perhaps derived from combining 'gambol', 'gambolier', and 'gamble', 'gambler'.

The song, "Son of a Gambolier" (in the DT), appeared in sheet music in 1870, and has been found by John Mehlberg in the 1869 edition of "Carmina Princetonia." It continues to exist as "Ramblin' Wreck from Georgia Tech."