Early Quenya
qalúmea Archaic
adjective. deadly
qalmea
adjective. deathly
qalma
adjective. deadly
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.
A set of related adjectives in the Qenya Lexicon of the 1910s: ᴱQ. qalma “deadly”, qalmea “deathly” and (archaic) †qalūmea equivalent to qalma, all based on ᴱQ. qalme or †qalume “death” (QL/76).
Neo-Quenya: Since [ᴹQ.] qualme “death” continued to appear in Tolkien’s later writings (Ety/KWAL), I’d adapt these adjectives as ᴺQ. qualmëa “deadly, deathly”, applied mainly to things apt to cause death.