Definition of unrelinquishable in US English:
unrelinquishable
adjective
That cannot be relinquished.
Origin
Mid 17th century; earliest use found in Henry More (1614–1687), philosopher, poet, and theologian. From un- + relinquish + -able.
Pronunciation
unrelinquishable
/(ˌ)ʌnrɪˈlɪŋkwɪʃəbl/