An Etymological Dictionary of Astronomy and Astrophysics

1. A long, pointed → metal  → bar.
   

2. Physics: A → transient variation in → voltage or → current in an → electric circuit.

Etymology (EN): M.E. spik(e) from O.N. spikr “nail;” akin to M.L.G. spiker “nail.”

Etymology (PE): Sixak, from six “spur, spit; thorn; any pointed thing,” + -ak a suffix of similarity and nuance.