肌着
はだぎ · hadagi · JLPT N2 · noun
underwear
肌 (skin) + 着 (worn on) = worn on the skin, so underwear
肌 means skin and 着 means to wear or put on. Something worn directly against the skin is underwear. Read it as 'skin-wear'.
着 — sheep 羊 (top) + eye 目 (bottom)
着 originated as a variant of 著, which depicted plants emerging visibly above ground (grass radical 艹 over 者). Over time 着 split off to carry meanings like 'attach,' 'wear,' or a verb suffix marking ongoing action (zhe), while 著 kept senses like 'manifest' or 'author.'