1.  ignition(n = noun.process) - the process of initiating combustion or catching fire;
is a kind of fire, flame, flaming
has particulars: spontaneous combustion
Derived form verb ignite₁

2.  ignition(n = noun.artifact) ignition system - the mechanism that ignites the fuel in an internal-combustion engine;
is a kind of mechanism
is a part of electrical system
has parts: distributer, distributor, electrical distributor, ignition coil, ignition switch, magneto, magnetoelectric machine, spark coil, spark gap, plug, spark plug, sparking plug

3.  ignition(n = noun.act) firing, inflammation, kindling, lighting - the act of setting something on fire;
is a kind of burning, combustion
Derived forms verb ignite₁, verb ignite₂

1.  The act of igniting, kindling, or setting on fire. [1913 Webster]

2.  The state of being ignited or kindled. Sir T. Browne. [1913 Webster]

ignition, n.
1 a mechanism for, or the action of, starting the combustion of mixture in the cylinder of an internal-combustion engine.
2 the act or an instance of igniting or being ignited.

Idiom:
ignition key a key to operate the ignition of a motor vehicle.

Etymology:
F ignition or med.L ignitio (as IGNITE)

N  calefaction, increase of temperature, heating, calefaction, tepefaction, torrefaction, melting, fusion, liquefaction, burning, ambustion, combustion, incension, accension, concremation, cremation, scorification, cautery, cauterization, ustulation, calcination, cracking, refining, incineration, cineration, carbonization, cupellation, ignition, inflammation, adustion, flagration, deflagration, conflagration, empyrosis, incendiarism, arson, auto dafe, boiling, coction, ebullition, estuation, elixation, decoction, ebullioscope, geyser, distillation (vaporization), furnace, blanket, flannel, fur, wadding, clothing, still, refinery, fractionating column, fractionating tower, cracking tower, match, incendiary, petroleuse, cauterizer, caustic, lunar caustic, alkali, apozem, moxa, acid, aqua fortis, aqua regia, catheretic, nitric acid, nitrochloro-hydric acid, nitromuriatic acid, radioactivity, gamma rays, alpha particles, beta rays, X-rays, radiation, cosmic radiation, background radiation, radioactive isotopes, tritium, uranium, plutonium, radon, radium, sunstroke, coup de soleil, insolation, pottery, ceramics, crockery, porcelain, china, earthenware, stoneware, pot, mug, terra cotta, brick, clinker, cinder, ash, scoriae, embers, soot, slag, coke, carbon, charcoal, wood alcohol, turpentine, tea tree oil, gasoline, kerosene, naptha, fuel oil (fuel), wax, paraffin, residue, tar, inflammability, combustibility, diathermancy, transcalency, conduction, convection, radiation, radiant heat, heat conductivity, conductivity, thermal expansion, coefficient of expansion, heated, molten, sodden, r_echauff_e, heating, adust, inflammable, combustible, diathermal, diathermanous, burnt, volcanic, radioactive.

ignition coil, ignition interlock, ignition key, ignition lock, ignition switch, ignition system