加答児[kataru] catarrh
愛児[aiji] beloved child
遺児[iji] orphan
育児[ikuji] childcare
育児院[ikujiin] orphanage

育児園[ikujien] baby nursery
育児時間[ikujijikan] nursing time
育児室[ikujishitsu] nursery
育児食[ikujishoku] baby food
育児法[ikujihou] child-rearing practice

双節棍[nunchaku] nunchaku (two linked fighting sticks)
一双[issou] pair (esp. of folding screens)
一卵性双生児[ichiranseisouseiji] identical twins
双紙[soushi] written work (esp. a bound text, as opposed to a scroll)
自己双対[jikosoutsui] self dual

双刃[moroha] double-edged
双暗車[souansha] twin propellers
双殻類[soukakurui] bivalves
双眼[sougan] both eyes