marlinspike n.

"large nail," mid-14c., perhaps from or related to a Scandinavian word, such as Old Norse spik "splinter," Middle Swedish spijk "nail," from Proto-Germanic *spikaz (source also of Middle Dutch spicher, Dutch spijker "nail," Old English spicing "large nail," Old English spaca, Old High German speihha "spoke"), from PIE root *spei- "sharp point" (source also of Latin spica "ear of corn," spina "thorn, prickle, backbone," and perhaps pinna "pin" (see pin (n.)); Greek spilas "rock, cliff;" Lettish spile "wooden fork;" Lithuanian speigliai "thorns," spitna "tongue of a buckle," Old English spitu "spit").

The English word also might be influenced by and partly a borrowing of Latin spica (see spike (n.2)), from the same root. Slang meaning "needle" is from 1923. Meaning "pointed stud in athletic shoes" is from 1832. Electrical sense of "pulse of short duration" is from 1935.

"to fasten (a ship) in a particular location by or as by cables, anchors, etc.," late 15c., probably related to Old English mærels "mooring rope," via unrecorded *mærian "to moor," or possibly borrowed from Middle Low German moren or Middle Dutch maren "to moor," from West Germanic *mairojan. Related: Moored, mooring. French amarrer is from Dutch.

large marine game-fish, 1917, shortening of marlinspike fish (1907), from marlinspike, name of a pointed iron tool used by sailors; the fish was so called from the shape of its elongated upper jaw.