implacable
im-PLAK-uh-buladjMeaning impossible to calm, please or change
Memory hook NOT PLACATE-ABLE. The children offer the roaring dragon a cake, a song and a bunch of flowers, but it roars on; it is not placate-able, it is implacable.
The implacable wind howled for three days without a pause.
In context Apologies, gifts and promises all failed; the old rival remained implacable, refusing even to shake hands at the reunion.
Similar relentless, unappeasable, unforgiving, unyielding
Opposite forgiving, yielding, lenient
From Latin implacabilis: in- (not) + placabilis (able to be calmed).