亡子 is read as ぼうし (boushi) and means dead child.
ぼうし
boushi
しきゅうないたいじしぼう
intrauterine fetal death (foetal)
ぼうめい
fleeing from one's country
ぼうふ
deceased husband
deceased father
なくす
to lose (through death; e.g. a wife, child)
なくなる
to die
なきあと
after one's death
ぼうこく
ruined country
もうじゃ
person who is obsessed (with money, power, etc.)
なきひと
the deceased
ぼうめいせいかつ
life in exile
ぼうめいせいけん
government in exile