Etymology: < Anglo-Norman rouncie, runci, runcin, Anglo-Norman and Old French, Middle French roncin, Old French ronci, (Picardy) ronsi horse used for carrying burdens (c1100; Middle French roucin , Middle French, French roussin derive from an unattested post-classical Latin variant *ruccinus ) < post-classical Latin runcinus (frequently from 11th cent. in British and continental sources; also roncinus ), further etymology uncertain and disputed: see Französisches etymol. Wörterbuch at *runcinus. Compare Old Occitan roci , rossin , roncin , etc. (late 12th cent.), Catalan rocí (15th cent.), Spanish rocín (first half of the 13th cent.; compare post-classical Latin rocinus (8th cent., and subsequently frequently from 12th cent., in Spanish sources)), Portuguese rocim (15th cent.; 1189 as †rucino ), and ( < French) Italian ronzino (1240). Since the French (and in general the Romance) nouns all denote a horse which is robust and used for carrying burdens, or (less usually) an old and decrepit horse, the English word apparently shows semantic amelioration, with which compare Middle Dutch runsine , (probably with suffix substitution) ronside , rosside , etc., Middle Low German runtsīt , Middle High German runzīt , all in sense ‘battle horse, charger’ (all < French); compare also Welsh rhwnsi , rownsi , etc. (13th cent.; probably < Middle English (although attested earlier) or perhaps < Anglo-Norman). Compare later roussin n. and also later Rosinante n.Apparently attested earlier as a surname (Roger Rouncy (1230), Ricardo Runcy (1299), etc.), although these may instead reflect the Anglo-Norman word.

Etymology: < rounce v.¹ (compare earlier rounce robble hobble n.) + either -y suffix¹ or -y suffix⁶.

Etymology: Origin uncertain. Either < rounce v.¹ + -y suffix⁶, or perhaps shortened < rouncival n. (compare sense 4 at that entry).