tinderyoudaoicibaDictYouDict
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’.
clump (v.1)youdaoicibaDictYouDict
"to heap or gather in clumps" (transitive), 1824, from clump (n.). Related: Clumped; clumping. Intransitive sense "to form a clump or clumps" is recorded from 1896.