Plimsoll line/ˈplɪmsəl laɪn; `plɪmsəl ˌlaɪn/ (also `Plimsoll mark / mɑ:k; ˌmɑrk/) line marked on a ship's side to show how far it may legally go down in the water when loaded （船的）载货吃水线.
牛津英汉双解词典