I. ˈrəst noun
( -s )
Etymology: Middle English, from Old English rūst; akin to Old Saxon, Old High German, & Old Swedish rost rust; derivative from the stem of English red (I)
1.
a. : the reddish porous brittle coating that is formed on iron especially when chemically attacked by moist air and that consists essentially of hydrated ferric oxide but usually contains some ferrous oxide and sometimes iron carbonates and iron sulfates — compare corrosion 1a, scale V 4a
b. : the somewhat similar coating produced on any of various other metals by corrosion — compare patina 2
c. : something resembling rust : accretion
this poem … under its accumulated rust and dirt of five centuries is fresh and living even today — G.G.Coulton
2.
a. obsolete : corrosive or injurious accretion or influence
how he glisters thorough my rust — Shakespeare
b. : an ill effect usually caused by idleness, inaction, or neglect
read to keep your mind from rust
lest through the rust of time … they should be lost to the world forever — Laurence Sterne
3.
a.
(1) or rust disease : any of numerous destructive diseases of plants produced by fungi of the order Uredinales and characterized by reddish brown pustular lesions on stems, leaves, or other plant parts — see apple rust , leaf rust , stem rust , stripe rust , wheat rust ; compare mildew , smut
(2) or rust fungus : a fungus of the order Uredinales — compare puccinia , uromyces
b. : any of several other fungus diseases of plants — usually used with a descriptive term; see white rust
c. : an abnormal reddish or brownish discoloration of vegetation or fruit
4. : a strong brown that is stronger and slightly yellower and lighter than average russet, lighter, stronger, and very slightly redder than average copper brown, and redder and deeper than gold brown
5. : a composition used in making a rust joint
II. verb
( -ed/-ing/-s )
Etymology: Middle English rusten, from rust, n.
intransitive verb
1. : to form rust : become oxidized — compare corrode vi 2, tarnish
2. : to degenerate in idleness : become dull, slow, or impaired especially by inaction, lack of use, or the passage of time
once-functioning objects now rusted and moldered in this cellar — Marcia Davenport
no man to let his power rust — Time
3. : to turn or become the color of rust : become reddish brown as if with rust
the leaves slowly rust
4.
a. : to be affected with a rust fungus
b. : to acquire a rusty appearance
transitive verb
1. : to cause (a metal) to form rust
keep up your bright swords, for the dew will rust them — Shakespeare
— compare corrode vt 1
2. : to impair or corrode by or as if by time, inactivity, or deleterious use
a six-year layoff … had not rusted his technique — Newsweek
3. : to blast or wither by or as if by the rust fungus
4. : to turn to the color of rust : cause to become reddish brown
the wind brought salt … rusting the crops — New York Times