1rare Assistance, backing; corroboration; = "support".
2Maintenance, sustenance; a means of livelihood or subsistence; = "support" 8. Now chiefly Jamaican.
Late 16th century; earliest use found in Abraham Fleming (c1552–1607), author, literary editor, and Church of England clergyman. Probably partly from support + -ance, and partly from Middle French supportance maintenance, sustenance, suffering, permission, help, indulgence from supporter + -ance.