The term samegawa (kanji: 鮫皮) means "shark skin" in English. It is written さめがわ in hiragana. It's pronounced roughly like "sah meh gah wah".
Literally, shark skin, but it specifically refers to shagreen, the material used for a katana’s grip and sheathe. 鮫, same, means shark and is sometimes found written in katakana: サメ.
皮, kawa, means skin or shed skin. Due to the linguistic phenomenon of sequential voicing, kawa is pronounced gawa in this case. The Chinese reading is hi and is found, for instance, in the Japanese word for human skin (hifu, 皮膚, ひふ).