"remaining part or quality, that which is left or remains," late 14c., contraction of remenant, remanent, remenaunt (c. 1300) "the remainder," from Old French remanant "rest, remainder, surplus," noun use of present participle of remanoir "to remain" (see remain (v.)).
Specific sense of "end of a piece of ribbon, drapery, cloth, etc." (that which remains after the last cutting of a bolt or web) is recorded from mid-15c. As an adjective, "remaining, left," 1540s. An Old English word for "remnant" was endlaf.