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

育成栽培[ikuseisaibai] vegetable and fruit growing
栽培[saibai] cultivation
栽培種[saibaishu] agricultural species
栽培所[saibaijo] plantation
純粋培養[junsuibaiyou] clean (pure) culture

促成栽培[sokuseisaibai] raising out-of-season crops with artificial heat
培う[tsuchikau] to cultivate
培養[baiyou] cultivation
培養液[baiyoueki] culture fluid
培地[baichi] culture medium