implacable
adjective /ɪmˈplækəbl/
/ɪmˈplækəbl/
- (of strong negative opinions or feelings) that cannot be changed
- implacable hatred
- (of a person) unwilling to stop opposing somebody/something
- an implacable enemy
- She remained implacable (= she would not change her feelings and opinions).
Word Originlate Middle English: from Latin implacabilis, from in- ‘not’ + placabilis (from placare ‘appease’).