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

双蹄[soutei] cloven foot
双蹄獸[souteijuu] cloven-hoofed animal
蹄鉄[teitetsu] horseshoe
馬蹄[batei] horse's hooves
馬蹄形[bateikei] horseshoe-shaped

偶蹄類[guuteirui] artiodactyls
有蹄類[yuuteirui] ungulates
蹄鉄工[teitetsukou] farrier
蹄叉[teisa] fourchette