— implacability, implacableness , n. — implacably , adv.
/im plak"euh beuhl, -play"keuh-/ , adj.
not to be appeased, mollified, or pacified; inexorable: an implacable enemy.
[ 1375-1425; late ME implacabilis. See IM- 2 , PLACABLE ]
Syn . unappeasable, unbending, merciless. See inflexible .