What does 手の甲 mean?
手の甲 is a Japanese noun meaning “back of one's hand” in English. It is written as 手の甲 in kanji, てのこう in hiragana, and tenokou in romaji. This word is part of JLPT N2 vocabulary.
Example sentence
手伝うって約束するよ。
I promise you I'll help you.