the.com/enmity
Friendship's evil twin, raised on grudges and fed by memory.
means A deep, settled, often mutual hostility between people or groups that endures over time.
from From Latin inimicus, literally not-friend (in- plus amicus), which strolled through Old French enemi to become both enemy and the feeling itself.
Same rootShares ancestry with enemy and amicable alike.
Built to lastImplies lasting hatred, not a passing flash of anger.
Legal cousinOld courts judged 'enmity' as motive for crimes.