一刀[ittou] sword
一刀彫り[ittoubori] one-knife carving
一刀両断[ittouryoudan] cutting in two with a single stroke
印刀[intou] seal-engraving knife
円刃刀[enjintou] round-edged scalpel

快刀[kaitou] (literary) sharp sword
快刀乱麻[kaitouranma] solving a problem swiftly and skillfully
懐刀[futokorogatana] confidant
儀刀[gitou] ceremonial sword
軍刀[guntou] saber

直向[hitamuki] earnest
安直[anchoku] inexpensive
一直[icchoku] lining out to first base
一直線[icchokusen] straight line
鉛直[enchoku] perpendicular

下駄直し[getanaoshi] repairing clogs
開き直る[hirakinaoru] to become defiant
気を取り直す[kiwotorinaosu] to completely rethink
急転直下[kyuutenchokka] suddenly and precipitately
居直る[inaoru] to sit up properly straight