Wiktionary
n. An unwanted or underachieving man, or occasionally a youngest son, sent by relatives to a distant land and sent regular remittances of upkeep money, in order that he doesn't come back.
WordNet
n. an exile living on money sent from home
Wikipedia
A remittance man is a historic term for an emigrant, often from Britain to a colony, supported by regular payments from home, on the expectation that he stay away.
Note that in this context, money is being sent in the opposite direction to today's usual usage of the term remittance, which means money that migrants send to their countries of origin.
Remittance Man (foaled 13 April 1984) was an Irish-bred, British-trained Thoroughbred racehorse who competed under National Hunt rules. He was noted for his consistency, excellent jumping and nervous temperament. Between December 1988 and April 1990 he competed in hurdle races, and showed promise by winning two of his twelve races including the Grade 2 Bristol Novices' Hurdle and never finishing worse than third. When switched to compete in steeplechases he showed immediate improvement and won thirteen of his first fourteen races over fences. In his first season of steeplechasing his wins included the Noel Novices' Chase, Wayward Lad Novices' Chase, Galloway Braes Novices' Chase and Arkle Challenge Trophy. He had his greatest success in the 1991/1992 season when he won the Arlington Premier Chase, Queen Mother Champion Chase and Melling Chase. In the following autumn he won the Desert Orchid Chase and the Peterborough Chase but then sustained a serious tendon injury. He won his comeback race in February 1994 but was beaten in his three remaining races.
Usage examples of "remittance man".
The remittance man thought he caught Thompson cheating and indiscreetly said so.
The remittance man went white, half rose from his seat, and shoved his head across the table toward the revolver.
A bad boy, a remittance man, a rogue company spy masquerading as a petty criminal—.
He had got himself rooted down in the Service like a remittance man half asleep in a hammock on some palm-shaded tropical beach, telling himself his luck would change some day and he'd get out of there.
DeMob gave me a reasonably secure cover identity as a playboy remittance man from a primogeniture polity, sent to while away his youth in less hidebound (and politically loaded) biomes, and it’.
The ambassadorship is a very polite way of making someone into a remittance man.
He was a remittance man with a remarkable constitution, and he lasted seven years.