instrument
instrument. 1. A written legal document that defines rights, duties, entitlements, or liabilities, such as a contract, will, promissory note, or share certificate. “An ‘instrument’ seems to embrace contracts, deeds, statutes, wills, Orders in Council, orders, warrants, schemes, letters patent, rules, regulations, bye-laws, whether in writing or in print, or partly in both; in fact, […]