The Collaborative International Dictionary
Marline \Mar"line\, n. [LG. marlien, marling, or D. marling, marlijn, fr. D. marren to tie, prob. akin to E. moor, v., and lijn line: cf.F. merlin. See Moor, v., Line.] (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. Marline-spike bird. [The name alludes to the long middle tail feathers.] (Zo["o]l.)
A tropic bird.
A jager, or skua gull.
Wiktionary
n. (alternative spelling of marlinspike English)
Usage examples of "marline spike".
And it was inconceivable that she would have gone - the Charlotte Meiner I knew would have clobbered you over the head with a marline spike.
If he thinks there's even a chance you're going to lay for him with a marline spike, he'll back off of you.