rusty

Etymology 1

From Middle English rusty, from Old English rūstiġ (“rusty”), from Proto-Germanic *rustagaz (“rusty”), equivalent to rust + -y. Cognate with Saterland Frisian rusterch (“rusty”), West Frisian rustich, roastich (“rusty”), Dutch roestig (“rusty”), German Low German rusterig, rüsterig (“rusty”), German rostig (“rusty”), Swedish rostig (“rusty”).

adj

1. Marked or corroded by rust.
2. Of the rust color, reddish or reddish-brown.
   Alive? he might be dead for aught I know, / With that red gaunt and colloped neck a-strain, / And shut eyes underneath the rusty mane; 1855, Robert Browning, Childe Roland to the Dark Tower Came, section XIV
3. Lacking recent experience, out of practice, especially with respect to a skill or activity.
   Before the match, Hodgson had expressed the hope that his players would be fresh rather than rusty after an 18-day break from league commitments because of two successive postponements. December 29, 2010, Sam Sheringham, “Liverpool 0-1 Wolverhampton”, in BBC
4. (now chiefly historical) Of clothing, especially dark clothing: worn, shabby.
   He wore a black jacket, rusty and amorphous. 1911, Max Beerbohm, Zuleika Dobson
5. Affected with the fungal plant disease called rust.

Etymology 2

Ellipsis of rusty one more often used for this, or from the general epithet rusty given to various particular firearm names—earlier both was applied in Cockney rhyming slang for other machines, including swords in their day, but the present coinage has not more than a loose connection to this and is from the preference for used or antique firearms due to their being easier or cheaper to obtain.

noun

1. (MLE, slang) A gun or in particular an old or worn one.
   My angles dusty, two black hands on the rusty 25-08-2014, Dimzy of 67 (lyrics and music), “Outside”, 1:29–1:35

Etymology 3

Variant form of resty; compare also reasty.

adj

1. Discolored and rancid; reasty.
   rusty bacon