A verb appearing as ᴱQ. qeletya “rot (intr.)” in the Qenya Lexicon with past tense qeleksine- and thus probably related to ᴱQ. qelet (qelekt-) “corpse”, both under the same early root ᴱ√QELE “perish, die, decay, fail” (QL/76). The present tense form of the verb therefore probably involves the sound change of ky > ty.

Neo-Quenya: Since ᴹQ. qelet “corpse” < ᴹ√KWEL appears in Tolkien’s later writings, I would retain ᴺQ. queletya- “to rot” as well.