The Qenya Lexicon of the 1910s had several similar adjectives under the early root ᴱ√QOLO: ᴱQ. qolda or qolina “ill” and ᴱQ. qolima “sickly, ailing” (QL/78).
Neo-Quenya: I’d adopt ᴺQ. quolina for all these meanings: “ill, sickly, ailing”. I would further assume it applies to any kind of physical ailment, including injury. For someone sick specifically by disease I would use [ᴺQ.] hlaiwa. Not all Neo-Quenya writers accept quo- as a valid combination; see the entry on how [[q|[wo] became [o]]] for further discussion.
A noun appearing as ᴱQ. alas (alast-) “marble” in the Qenya Lexicon of the 1910s derived from primitive ᴱ✶ʒalast- (QL/30).
Neo-Quenya: I think this word may be salvageable in Neo-Quenya as ᴺQ. alas, reconceived as a derivative of ᴹ√GALAS “joy, be glad”, perhaps from ᴺ✶galast- originally with the sense “thing pleasant to touch”.