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"document or book written by hand," 1590s (adj.), c.1600 (n.), from Medieval Latin manuscriptum "document written by hand," from Latin manu scriptus "written by hand," from manu, ablative of manus "hand" (see manual (adj.)) + scriptus (neuter scriptum), past participle of scribere "to write" (see script (n.)). Abbreviation is MS, plural MSS.