1. 点燃;(使)燃烧;着火
    When you ignite something or when it ignites, it starts burning or explodes.

    e.g. The bombs ignited a fire which destroyed some 60 houses...
           炸弹引发的大火烧毁了大约 60 栋房屋。
    e.g. The blasts were caused by pockets of methane gas that ignited.
           爆炸是由甲烷气囊被引燃造成的。

2. 激起;使激动
    If something or someone ignites your feelings, they cause you to have very strong feelings about something.

    e.g. There was one teacher who really ignited my interest in words...
           曾经有一位老师真正激起了我对文字的兴趣。
    e.g. The recent fighting in the area could ignite regional passions far beyond the borders.
           最近该地区的战斗可能激发边境以外整个地区的激动情绪。