Early 18th century; earliest use found in Nathan Bailey (d. 1742), lexicographer and schoolmaster. From classical Latin rūbīgin-, rūbīgō rust, blight + -ose.
Definition of rubiginose in US English:
rubiginose
adjective
Botany Zoology
Rust-coloured; rubiginous.
Origin
Early 18th century; earliest use found in Nathan Bailey (d. 1742), lexicographer and schoolmaster. From classical Latin rūbīgin-, rūbīgō rust, blight + -ose.