1800-10, Americanism; < Canadian French,French: a flowing, noun use of feminine of coulé, past participle of couler to flow < Latincōlāre to filter, strain, derivative of cōlum strainer, sieve; cf. colander, portcullis
"deep ravine, seasonally flooded," 1804, a North American word, originally in areas explored by French trappers, from French coulée "flow" (17c.), from fem. past participle of couler "to flow," from Latin colare "to filter, strain" (see colander).