無腰 is read as むごし (mugoshi) and means unarmed.
むごし
mugoshi
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
むすう
innumerable
むこう
invalid