D defs.my
Entry 1 sense Webster, 1913

Sea letter

/sē lĕt'-ẽr/ · Sea· let·ter · IPA
01 The customary certificate of national character which neutral merchant vessels are bound to carry in time of war; a passport for a vessel a…
  1. 1.
    The customary certificate of national character which neutral merchant vessels are bound to carry in time of war; a passport for a vessel and cargo.(Mar. Law.)