吊 has multiple uses: 吊灯 (chandelier), 吊车 (crane), 吊桥 (suspension bridge), 吊唁 (condolences). As a measure word, 一吊钱 was an old unit of currency (a string of coins).
memory
Picture something dangling from a hook — that's the core meaning. The 口 (mouth) at the top is like the hook, with the vertical stroke hanging down.
