n.

1. 著火；燃燒[U]
   The ignition of the forest was caused by lightning.

   森林起火是由雷電引起的。

2. 【機】點火，發火；點火開關，發火裝置[the S]
   turn on the ignition

   開點火開關

3. 【化】灼燒[U]

n.

1. the action of igniting or the state of being ignited.
2. the starting of the combustion of fuel in the cylinders of an internal-combustion engine.