無害 is read as むがい (mugai) and means harmless.
むがい
mugai
むこうがい
unpolluted
むえきゆうがい
useless and harmful
むがいつうこうけん
the right of innocent passage
むがいつうこう
innocent passage
ゆうえきむがい
beneficial and harmless
ゆうがいむえき
more harm than good
むじん
shorthandedness
むちゃ
rash
むりやり
forcibly
むり
impossible
むりょう
free (of charge)
ぶじ
good health