「高い」 (Takai) is an i-adjective with multiple meanings: 'expensive' (for price), 'high' (for level, sound, or position), and 'tall' (for height). The specific meaning depends heavily on the context in which it is used.

「高(たか)い」は「expensive, high, tall」など、文脈(ぶんみゃく)によって意味(いみ)が変わ(か)るい形容詞(けいようし)です。