coco de mer (d? ?m??) n1. (Plants) a palm tree, Lodoicea maldivica, of the Seychelles, producing a large fruit containing a two-lobed edible nut2. (Plants) the nut of this palm Also called: double coconut [French: coconut of the sea]Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014