無口 is read as むこう (mukou) and means astomatous.
むこう
mukou
くちなし
non-functional mouth
くちほどにもない
all bark and no bite
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
むしょく
without an occupation
むごん
silence (not speaking)
むせん
radio (communication)
むよう
unnecessary