Rust — Defs

01 n. The reddish yellow coating formed on iron when exposed to moist air, consisting of ferric oxide or hydroxide; hence, by extension, any meta…

1.
The reddish yellow coating formed on iron when exposed to moist air, consisting of ferric oxide or hydroxide; hence, by extension, any metallic film of corrosion.(Chem.)
2.
A minute mold or fungus forming reddish or rusty spots on the leaves and stems of cereal and other grasses (Trichobasis Rubigo-vera), now usually believed to be a form or condition of the corn mildew (Puccinia graminis). As rust, it has solitary reddish spores; as corn mildew, the spores are double and blackish.(Bot.)
3.
That which resembles rust in appearance or effects.
“Sacred truths cleared from all rust and dross of human mixtures.” — Eikon Basilike.

Phrases & compounds

Rust joint — a joint made between surfaces of iron by filling the space between them with a wet mixture of cast-iron borings, sal ammoniac, and sulphur, which by oxidation becomes hard, and impervious to steam, water, etc.

Rust mite — a minute mite (Phytopius oleivorus) which, by puncturing the rind, causes the rust-colored patches on oranges.

02 v. i. To contract rust; to be or become oxidized.

imp. & p. p. Rusted; p. pr. & vb. n. Rusting

1.
To contract rust; to be or become oxidized.
“If gold ruste, what shall iron do?” — Chaucer.

“Our armors now may rust.” — Dryden.
2.
To be affected with the parasitic fungus called rust; also, to acquire a rusty appearance, as plants.
3.
To degenerate in idleness; to become dull or impaired by inaction.Fig.:
“Must I rust in Egypt? never more Appear in arms, and be the chief of Greece?” — Dryden.

03 v. t. To cause to contract rust; to corrode with rust; to affect with rust of any kind.

1.
To cause to contract rust; to corrode with rust; to affect with rust of any kind.
“Keep up your bright swords, for the dew will rust them.” — Shak.
2.
To impair by time and inactivity.Fig.: