IPA: /juːˈnɔɪld/
KK: /ˈjuːˌnɔɪld/
Not having been treated with oil, often referring to machinery or tools that require lubrication to function properly.
The machine was running poorly because it was unoiled for too long.
Unoiled → It is formed from "un-" (meaning not) and "oiled" (from the Old English "āleah", meaning to smear or anoint with oil). The word "unoiled" means not smeared or anointed with oil.
Think of 'not' ('un-') having oil applied ('oiled') — that's why unoiled means something that hasn't been oiled.