1.【航】上桅(帆)
1.上桅(帆)的;最高[上]的
1.a ship's mast that is taller than a topmast or is an extension of a topmast
2.a sail set on a topgallant mast
1.A support or brace, especially the iron crosstree on a topgallant masthead.
撑杆或支柱,尤指上桅桅顶的铁横桁