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

に対して[nitaishite] towards
に対する[nitaisuru] regarding
テロ対策[terotaisaku] anti-terrorist
安全対策[anzentaisaku] safety measure
一対[ittsui] pair

１対一[ichitaiichi] one-to-one
応対[outai] receiving
空対空[kuutaikuu] air-to-air
空対地[kuutaichi] air-to-surface
空対地ミサイル[kuutaichimisairu] air-to-surface missile

一己[ikko] personal
乎己止点[okototen] marks to aid in reading Chinese classics
己れ[onore] oneself (itself, etc.)
克己[kokki] self denial
克己心[kokkishin] spirit of self-denial

自己[jiko] self
自己暗示[jikoanji] self suggestion
自己規制[jikokisei] self regulation
自己犠牲[jikogisei] self-sacrifice
自己共役[jikokyouyaku] self adjoint

貨物自動車[kamotsujidousha] truck
各自[kakuji] individual
観自在[kanjizai] Avalokitesvara (bodhisattva)
結社の自由[kesshanojiyuu] freedom of association
現金自動支払機[genkinjidoushiharaiki] cash dispenser

現金自動預け払い機[genkinjidouazukebaraiki] automatic teller machine
現金自動預金支払機[genkinjidouyokinshiharaiki] automatic teller machine
古自動車[furujidousha] used car
後追い自殺[atooijisatsu] following someone's example, and committing suicide
最小自乗法[saishoujijouhou] least-squares method