Late Middle English; earliest use found in John Lydgate (c1370–c1449), poet and prior of Hatfield Regis. From Middle French monstrueux and its etymon classical Latin mōnstruōsus, variant of mōnstrōsus.
Definition of monstruous in US English:
monstruous
adjectiveˈmɒnstrʊəs
rare
Monstrous.
Origin
Late Middle English; earliest use found in John Lydgate (c1370–c1449), poet and prior of Hatfield Regis. From Middle French monstrueux and its etymon classical Latin mōnstruōsus, variant of mōnstrōsus.