発勁[hakkei] release internal power
勁捷[keishou] strong and nimble
勁卒[keisotsu] excellent soldier
勁敵[keiteki] formidable foe

勁悍[keikan] strong and fierce
雄勁[yuukei] vigorous
勁草[keisou] wind-resistant blade of grass

草臥れる[kutabireru] to get tired
遺草[isou] posthumous works
一年草[ichinensou] annual (plant)
詠草[eisou] draft poem
下草[shitakusa] undergrowth

仮名草紙[kanazoushi] story in the kana
伽草子[togizoushi] fairy-tale book
海草[kaisou] marine plant
乾草[kansou] hay
甘草[kanzou] liquorice