tinder
noun [ U ] uk/ˈtɪn.dər/ us/ˈtɪn.dɚ/
火种;引火物
small pieces of something dry that burns easily, used for lighting fires
We used some dry grass as tinder to light the campfire. 我们用一些干草作为引子来点燃篝火。
The grass is tinder-dry (= so dry that it will burn easily), so there's a risk of fire. 草非常干，一点就着，所以有发生火灾的危险。
Synonym: kindling