Definition of unloosable in US English:

unloosable

(also unlooseable)

adjective

  • Incapable of being loosened or undone.

Origin

Late Middle English; earliest use found in Arderne's Treatises of Fistula in Ano. From un- + loose + -able.

Pronunciation

unloosable

/(ˌ)ʌnˈluːsəbl/