拝啓
はいけい · haikei · JLPT N1 · noun
-- a formal greeting used at the beginning of a letter --
✉️ 拝 = bow respectfully + 啓 = open: a formal letter opens with a respectful bow
拝 means to bow or revere; 啓 means to open or address. Together they mark the formal opening of a letter. It pairs with 敬具 (keigu), the formal closing.