ちょっと一杯[chottoippai] let's have a quick drink
ばつ一[batsuichi] being once divorced
一向[hitaburu] nothing but
サラダ一皿[saradahitosara] plate of salad

安全第一[anzendaiichi] safety first
一か八か[ichikabachika] sink or swim
一っ走り[hitoppashiri] spin (as in 'take a car for a spin')
一つ一つ[hitotsuhitotsu] one-by-one

まっ四角[masshikaku] square
一天四海[ittenshikai] the world
下四半期[shimoshihanki] last quarter (of the year)
弦楽四重奏曲[gengakushijuusoukyoku] string quartet
再三再四[saisansaishi] repeatedly

三寒四温[sankanshion] alternation of three cold and four warm days
四つ[yottsu] four
四つんばい[yotsunbai] (crawl) on all fours
四つ角[yotsukado] four corners
四つ足[yotsuashi] four-footed (animal)

亜炭[atan] lignite
一酸化炭素[issankatanso] carbon monoxide
活性炭[kasseitan] activated charcoal
褐炭[kattan] brown coal
含水炭素[gansuitanso] carbohydrate

黒炭[kokutan] bituminous coal
採炭[saitan] coal mining
載炭[saitan] coaling
重炭酸曹達[juutansansouda] sodium bicarbonate
出炭[shuttan] coal production

バイオ素子[baiososhi] bio-device
弗素[fusso] fluorine (F)
一酸化炭素[issankatanso] carbon monoxide
栄養素[eiyouso] nutrient
塩化水素[enkasuiso] hydrogen chloride

塩素[enso] chlorine (Cl)
塩素酸[ensosan] chloric acid
塩素酸塩[ensosanen] chlorate
音楽の素質[ongakunososhitsu] aptitude for music
音素[onso] phoneme