From WordNet (r) 3.0 (2006):
rust
adj 1: of the brown color of rust [syn: rust, rusty, rust-
brown]
n 1: a red or brown oxide coating on iron or steel caused by the
action of oxygen and moisture
2: a plant disease that produces a reddish-brown discoloration
of leaves and stems; caused by various rust fungi
3: the formation of reddish-brown ferric oxides on iron by low-
temperature oxidation in the presence of water [syn: rust,
rusting]
4: any of various fungi causing rust disease in plants [syn:
rust, rust fungus]
v 1: become destroyed by water, air, or a corrosive such as an
acid; "The metal corroded"; "The pipes rusted" [syn:
corrode, rust]
2: cause to deteriorate due to the action of water, air, or an
acid; "The acid corroded the metal"; "The steady dripping of
water rusted the metal stopper in the sink" [syn: corrode,
eat, rust]
3: become coated with oxide