implacable
adjective
[ ɪmˈplakəb(ə)l ]
• unable to be appeased or placated.
• "he was an implacable enemy of Ted's"
Similar:
unappeasable,
unpacifiable,
unplacatable,
unmollifiable,
unforgiving,
unsparing,
grudge-holding,
inexorable,
intransigent,
adamant,
determined,
unshakeable,
unswerving,
unwavering,
inflexible,
unyielding,
unbending,
uncompromising,
unrelenting,
relentless,
ruthless,
remorseless,
merciless,
pitiless,
heartless,
cruel,
hard,
harsh,
stern,
steely,
tough,
Origin:
late Middle English: from Latin implacabilis, from in- ‘not’ + placabilis (see placable).
