tinder: [OE] Tinder, and its relatives German zunder, Dutch tonder, and Swedish tunder, go back to a prehistoric Germanic base *tund- ‘ignite, kindle’, which also produced German anzünden, Swedish upptända, and Danish antænde ‘kindle’. Its ultimate origins are not known. The now clichéd tinder-dry is first recorded in Rudyard Kipling’s Light That Failed 1891: ‘the tinder-dry clumps of scrub’.
tinder (n.)
"dry, inflammable substance," Old English tynder, from or related to tendan "to kindle," from Proto-Germanic *tund- "ignite, kindle" (cognates: Gothic tandjan, Swedish tända, German zünden "to kindle").