tinder

noun

1. a highly flammable material or preparation formerly used for catching the spark from a flint and steel struck together for fire or light.
2. any dry substance that readily takes fire from a spark.

noun

1. dry wood or other easily combustible material used for lighting a fire
2. anything inflammatory or dangeroushis speech was tinder to the demonstrators’ unrest

n.“dry, inflammable substance,” Old English tynder, related to tendan “to kindle,” from Proto-Germanic *tund- “ignite, kindle” (cf. Gothic tandjan, Swedish tända, German zünden).