伍長 is read as ごちょう (gochou) and means corporal.
ごちょう
gochou
ごする
to rank with
はんちょう
squad leader
たいちょう
commanding officer
ゆうちょう
leisurely
じゅくちょう
principal of a private school
かんちょう
captain (of a warship)
れいちょう
crown (of creation)
だいいちぶちょう
assistant chief of staff, g1
だいにぶちょう
assistant chief of staff, g2
だいさんぶちょう
assistant chief of staff, g3
けんじちょう
superintending prosecutor
けんじそうちょう
prosecutor general