Rosin is from a variant of resin, from Old French raisine, resine, from Latin resina ('resin'), itself probably from Ancient Greek rhētinē ('resin of the pine'). The historical chain includes Latin resina and Ancient Greek rhētinē. Older glosses in the chain include "resin" and "resin of the pine", which help explain the semantic range of the modern word. Morphologically, rosin is best read as borrowing, yielding an English noun and verb shaped by both form history and later usage. In current English it functions as a noun and verb, with the sense "a hard resin from pine used on bow strings; to treat with it". English derivatives include rosined and rosiny; related forms include resin. The result is an English noun and verb whose etymology preserves the older forms while supporting the word's specialized modern meaning.