/rust/ , n.
1. Also called iron rust . the red or orange coating that forms on the surface of iron when exposed to air and moisture, consisting chiefly of ferric hydroxide and ferric oxide formed by oxidation.
2. any film or coating on metal caused by oxidation.
3. a stain resembling this coating.
4. any growth, habit, influence, or agency tending to injure, deteriorate, or impair the mind, character, abilities, usefulness, etc.
5. Plant Pathol.
a. any of several diseases of plants, characterized by reddish, brownish, or black pustules on the leaves, stems, etc., caused by fungi of the order Uredinales.
b. Also called rust fungus . a fungus causing this disease.
c. any of several other diseases of unknown cause, characterized by reddish-brown spots or discolorations on the affected parts.
6. reddish yellow, reddish brown, or yellowish red.
v.i.
7. to become or grow rusty, as iron.
8. to contract rust.
9. to deteriorate or become impaired, as through inaction or disuse.
10. to become rust-colored.
v.t.
11. to affect with rust.
12. to impair as if with rust.
13. to make rust-colored.
14. rust out , (of metal pipes, machinery, etc.) to decay and become unusable through the action of rust.
15. rust through , to develop holes, breaks, or the like, because of rust.
16. rust together , to join two metal pieces, as iron pipes, by causing the joint to rust.
adj.
17. having the color rust.
[ bef. 900; (n.) ME; OE rust; c. G Rost; (v.) ME rusten, deriv. of the n.; akin to RED ]
Syn. 2. corrosion. 9. decay, decline.