originally a variant spelling and pronunciation of inhuman "cruel, hard-hearted;" it appears to have died out 17c. but returned c. 1822, probably a reformation as a negative of humane (q.v.), with its accent.
biological weapons are considered too inhumane to be used
inhibitor
inhibitory
inhospitable
in-house
inhuman
inhumane
inhumanity
inhumation
inhume
Inigo
inimical