The Collaborative International Dictionary of English v.0.48:

Spike \Spike\, n. [Akin to LG. spiker, spieker, a large nail, D.
   spijker, Sw. spik, Dan. spiger, Icel. sp[imac]k; all perhaps
   from L. spica a point, an ear of grain; but in the sense of
   nail more likely akin to E. spoke of a wheel. Cf. Spine.]
   1. A sort of very large nail; also, a piece of pointed iron
      set with points upward or outward.
      [1913 Webster]

   2. Anything resembling such a nail in shape.
      [1913 Webster]

            He wears on his head the corona radiata . . .; the
            spikes that shoot out represent the rays of the sun.
                                                  --Addison.
      [1913 Webster]

   3. An ear of corn or grain.
      [1913 Webster]

   4. (Bot.) A kind of flower cluster in which sessile flowers
      are arranged on an unbranched elongated axis.
      [1913 Webster]

   Spike grass (Bot.), either of two tall perennial American
      grasses (Uniola paniculata, and Uniola latifolia)
      having broad leaves and large flattened spikelets.

   Spike rush. (Bot.) See under Rush.

   Spike shell (Zool.), any pteropod of the genus Styliola
      having a slender conical shell.

   Spike team, three horses, or a horse and a yoke of oxen,
      harnessed together, a horse leading the oxen or the span.
      [U.S.]
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Spike \Spike\, v. t. [imp. & p. p. Spiked; p. pr. & vb. n.
   Spiking.]
   1. To fasten with spikes, or long, large nails; as, to spike
      down planks.
      [1913 Webster]

   2. To set or furnish with spikes.
      [1913 Webster]

   3. To fix on a spike. [R.] --Young.
      [1913 Webster]

   4. To stop the vent of (a gun or cannon) by driving a spike
      nail, or the like into it.
      [1913 Webster]
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Spike \Spike\, n. [Cf. G. spieke, L. spica an ear of grain. See
   Spikenard.] (Bot.)
   Spike lavender. See Lavender.
   [1913 Webster]

   Oil of spike (Chem.), a colorless or yellowish aromatic oil
      extracted from the European broad-leaved lavender, or
      aspic (Lavendula Spica), used in artist's varnish and in
      veterinary medicine. It is often adulterated with oil of
      turpentine, which it much resembles.
      [1913 Webster]

WordNet (r) 3.0 (2006):

spike
    n 1: a transient variation in voltage or current
    2: sports equipment consisting of a sharp point on the sole of a
       shoe worn by athletes; "spikes provide greater traction"
    3: fruiting spike of a cereal plant especially corn [syn: ear,
       spike, capitulum]
    4: (botany) an indeterminate inflorescence bearing sessile
       flowers on an unbranched axis
    5: a sharp rise followed by a sharp decline; "the seismograph
       showed a sharp spike in response to the temblor"
    6: a very high narrow heel on women's shoes [syn: spike heel,
       spike, stiletto heel]
    7: each of the sharp points on the soles of athletic shoes to
       prevent slipping (or the shoes themselves); "the second
       baseman sharpened his spikes before every game"; "golfers'
       spikes damage the putting greens"
    8: a sharp-pointed projection along the top of a fence or wall
       (or a dinosaur)
    9: a long, thin sharp-pointed implement (wood or metal); "one of
       the spikes impaled him"
    10: any holding device consisting of a rigid, sharp-pointed
        object; "the spike pierced the receipts and held them in
        order" [syn: spike, spindle]
    11: a large stout nail; "they used spikes to fasten the rails to
        a railroad tie"
    v 1: stand in the way of
    2: pierce with a sharp stake or point; "impale a shrimp on a
       skewer" [syn: transfix, impale, empale, spike]
    3: secure with spikes
    4: bring forth a spike or spikes; "my hyacinths and orchids are
       spiking now" [syn: spike, spike out]
    5: add alcohol to (beverages); "the punch is spiked!" [syn:
       spike, lace, fortify]
    6: manifest a sharp increase; "the voltage spiked"

Moby Thesaurus II by Grady Ward, 1.0:

211 Moby Thesaurus words for "spike":
   adulterate, ament, annul, auger, auricle, baffle, balk, bastardize,
   bayonet, bite, blast, block, bore, bramble, brave, brier, bristle,
   broach, bugger, bung, burr, cactus, cancel, capitulum, catchweed,
   catkin, challenge, check, check valve, checkmate, circumvent,
   cleavers, cob, cock, cone, confound, confront, contaminate,
   contravene, cork, corncob, corrupt, corymb, counter, counteract,
   countermand, countersink, counterwork, cripple, cross, cut, cyme,
   dagger, dash, de-energize, debase, debilitate, defeat, defy,
   denaturalize, denature, destroy, dilute, dirk, disable, disarm,
   discomfit, disconcert, discountenance, disenable, dish, disrupt,
   doctor, doctor up, drain, drill, drug, ear, ear of corn, elude,
   empierce, enfeeble, equipage, faucet, fix, flummox, foil, fortify,
   four-in-hand, frustrate, goose grass, gore, gouge, gouge out,
   hamstring, head, hole, honeycomb, hors de combat, impale,
   inactivate, incapacitate, kibosh, knife, knock the chocks, lace,
   lame, lance, lid, maim, mealie, nail, needle, nettle, nonplus,
   nullify, pair, panicle, peg, penetrate, perforate, perplex, picket,
   pierce, pike, pin, pine cone, pine needle, pink, plug, plunge in,
   poison, pollute, poniard, prick, prickle, prong, punch, puncture,
   put, queer, queer the works, quill, raceme, randem, ream, ream out,
   riddle, rig, ruin, run through, saber, sabotage, scotch, sea cock,
   skewer, spadix, span, spear, spicule, spiculum, spigot, spike team,
   spikelet, spile, spill, spine, spit, spoil, stab, stake, stick,
   sticker, stiletto, stonewall, stop, stopgap, stopper, stopple,
   strengthen, strobile, stump, sword, tamper with, tandem, tap, team,
   thistle, thorn, three-up, thwart, thyrse, transfix, transpierce,
   treenail, trepan, trephine, turnout, umbel, unfit, unicorn, upset,
   valve, verticillaster, void, water, water down, weaken, wing,
   wreck, yucca



The Jargon File (version 4.4.7, 29 Dec 2003):

spike
 v.

    1. To defeat a selection mechanism by introducing a (sometimes temporary)
    device that forces a specific result. The word is used in several
    industries; telephone engineers refer to spiking a relay by inserting a pin
    to hold the relay in either the closed or open state, and railroaders refer
    to spiking a track switch so that it cannot be moved. In programming
    environments it normally refers to a temporary change, usually for testing
    purposes (as opposed to a permanent change, which would be called 
    hardwired).

    2. [borderline techspeak] A visible peak in an otherwise rather constant
    graph (e.g. a sudden surge in line voltage, an unexpected short ?high? on a
    logical line in a circuit). Hackers frequently use this for a sudden short
    increase in some quantity such as system load or network traffic.


The Free On-line Dictionary of Computing (30 December 2018):

spike

    To defeat a selection mechanism by introducing a
   (sometimes temporary) device that forces a specific result.
   The word is used in several industries; telephone engineers
   refer to spiking a relay by inserting a pin to hold the relay
   in either the closed or open state, and railroaders refer to
   spiking a track switch so that it cannot be moved.  In
   programming environments it normally refers to a temporary
   change, usually for testing purposes (as opposed to a
   permanent change, which would be called hard-coded).

   (1999-10-18)