IPA: /ˈluːsənər/
KK: /ˈlusənər/
An object or substance that makes something less tight or more relaxed.
The loosener helped to make the screws easier to remove.
Loosener → It is formed from "loose" (from Old English *losian*, meaning to lose or set free) and "-er" (meaning a person who). A loosener is a person or thing that makes something loose or free.
Think of someone or something that 'sets free' ('loose') — that's why a loosener is something that makes things loose.