implacable
adjective C2
Plain meaning
impossible to calm, satisfy, or persuade to stop opposing something
Exam-register meaning
unyielding and not open to appeasement or compromise
In context
naturalShe remained implacable even after they apologised.
examThe regime faced implacable opposition from groups excluded from political power.
Common collocations
implacable enemyimplacable oppositionimplacable hostility
Watch out
Do not confuse implacable with impossible; implacable describes a person/force that cannot be softened.
Word family
implacability (noun)implacably (adverb)