[mass noun]the action of setting something on fire or starting to burn 点火,着火 three minutes after ignition, the flames were still growing. 点火后三分钟,火焰仍越烧越高。 ■the process of starting the combustion of fuel in the cylinders of an internal-combustion engine (内燃机汽缸燃料的)发火 ■[count noun](一般作 the ignition)the mechanism for bringing this about, typically activated by a key or switch (尤指以钥匙、开关发动的)发火装置 he put the key in the ignition. 他把钥匙插入发火装置。
语源
early 17th cent. (denoting the heating of a substance to the point of combustion or chemical change): from medieval Latin ignitio(n-), from the verb ignire 'set on fire' (see ignite)