naifu-gata sekki (knife blade ): a kind of stone tools developed from sekijin ナイフ形石器 (Knife Blade)石刃から創り出した石器の一種。
stone tools resembling a knife were characteristics to the end period of the paleolithic period , and they were made by blunting and exfoliating flakes like stone knives (blades ) (i .e . exfoliation was adjusted so that the sharp edge of flake would be partly remained like a knife blade and the rest of the edge would be blunted ), and by forming the flakes into a shape similar to modern knives . ナイフ形石器（ナイフがた せっき）とは、後期旧石器時代に特徴的な、石刃（刃器）などの剥片に刃潰し剥離（剥片自身がもつ鋭い側縁の一部をナイフの刃のように残し、ほかの側縁を鈍くつぶす調整剥離）を加え、現在のナイフに似た形に仕上げた石器である。
