Mar·line n.  Naut. A small line composed of two strands a little twisted, used for winding around ropes and cables, to prevent their being weakened by fretting.
 Marline spike, Marling spike Naut., an iron tool tapering to a point, used to separate the strands of a rope in splicing and in marling. It has an eye in the thick end to which a lanyard is attached. See Fid. [Written also marlin spike]
 Marline-spike bird. [The name alludes to the long middle tail feathers.] Zool. (a) A tropic bird. (b) A jager, or skua gull.