Word Origin & History
marlin"large marine game-fish," 1917, shortening of marlinspike "pointed iron tool used by sailors to separate strands of rope" (1626), from M.Du. marlijn "small cord," from marlen "to fasten or secure (a sail)," probably freq. of M.Du. maren "to tie, moor." The fish was so called from the shape of its elongated
upper jaw.