Early Primitive Elvish
tuřu
root. TUŘU
turu
root. am strong
tuðu
root. kindle
There are more words but they are from Tolkien's earlier conceptional periods. Tolkien likely changed these words as he evolved the aesthetics and completeness of the languages. You may even find languages that Tolkien later rejected. Do not mix words from different time periods unless you are familiar with the phonetic developments.
Below: Tolkien's Late Period (1950–1973). These are from Tolkien's late conceptual period — his most settled forms of the languages. Prefer these over the earlier ones above when composing new text.
The root ᴱ√TUŘU “kindle” [TUÐU] appeared in the Qenya Lexicon of the 1910s with variant forms ᴱ√TUSO and ᴱ√TUSU as well as derivatives like ᴱQ. tunda- “kindle”, ᴱQ. turu “wood, properly firewood”, and ᴱQ. tusturin “match” (QL/96). The contemporaneous Gnomish Lexicon had a similar primitive form tudh- with derivatives like G. tund “log for the fire”, G. tusta- “inflame, kindle, set light to, burn”, and G. tuthli “match” (GL/72). However, the Gnomish Lexicon also had words like G. drui “wood, forest” and G. duru “wood; a pole, beam, or log” (GL/31). Since initial d- > t- in Early Qenya, it seems likely that ᴱ√TUŘU “kindle” may also represent a blending with an unattested root ✱ᴱ√DURU “wood”.
Many years later Tolkien gave a hypothetical root √TUD in contrasted to √TUL to illustrate certain principles of etymological variations (VT48/25). It is not clear whether this √TUD is related to earlier ᴱ√TUÐU “kindle”. Nevertheless, I think it is worth positing a Neo-Root ᴺ√TUD “firewood, kindling” to salvage Early Qenya and Gnomish words of similar meaning.