instrument(redirected from plastic instrument)
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A formal or legal written document; a document in writing, such as a deed, lease, bond, contract, or will. A writing that serves as evidence of an individual's right to collect money, such as a check.
n. 1) a written legal document such as a contract, lease, deed, will or bond. 2) an object used to perform some task or action, ranging from a surgeon's scalpel to any hard thing used in an assault (a blunt instrument).
instrumenta written legal document. See also NEGOTIABLE INSTRUMENT.
INSTRUMENT, contracts. The writing which contains some agreement, and is so called because it has been prepared as a memorial of what has taken place or been agreed upon. The agreement and the instrument in which it is contained are very different things, the latter being only evidence of the existence of the former. The instrument or form of the contract may be valid, but the contract itself may be void on account of fraud. Vide Ayl. Parerg. 305; Dunl. Ad. Pr. 220.