Meaning

noun the residue that remains after animal fat has been rendered

noun armor plate that protects legs below the knee

originFrom Low German (compare German Low German Greev, Greve (“greaves”)), from Middle Low German grêve, from Old Saxon *griovo, from Proto-West Germanic *greubō (“roughage, brushwood, kindling”), perhaps related to *grubaz (“rough, coarse”), the root of German Griebe (“greaves, crackling”). Possibly related to gruff. Also compare Old High German grob (“coarse”) (modern German grob).

Etymology from Wiktionary, CC BY-SA 3.0