IPA: /ʌnˈrʌstɪd/
KK: /ʌnˈrʌstɪd/
Not covered with rust; in a clean and shiny condition.
The unrusted metal parts of the bike looked brand new.
Unrusted → It is formed from the prefix "un-" (meaning not) and the root "rust" (from Old English "rust", meaning the reddish-brown oxide that forms on iron). The word "unrusted" means not affected by rust or free from rust.
Think of 'not' ('un-') being added to 'rust' — so unrusted means something that is not rusty.