Q. *mixa adj. “sharp-pointed”
An adjective meaning “sharp-pointed” appearing in notes explaining the etymology of the name S. Maeglin from around 1971 (WJ/337, 339 note #10). Christopher Tolkien wrote this word as miχa with a χ (Greek chi), but the primitive form of this word was given as ✶mikrā. Since ancient [r] became [s] after voiceless stops like [k] in Quenya (PE19/83), it is more likely this word was pronounced [miksa], and the actual form was mixa (that is with an “x”).
Reference ✧ WJ/337 ✧ miχa “sharp-pointed”
|✶mikrā > miχa||[mikrā] > [miksā] > [miksa]||✧ WJ/337|