soloist n.

1690s, "piece of music intended for one voice or instrument," also a performance of such, from Italian solo, literally "alone," from Latin solus "alone" (see sole (adj.)). In reference to dance from 1794. As an adjective in English from 1712, originally in the non-musical sense of "alone, unassisted." Of musicians or instruments, "play a solo part," 1862. in reference to aircraft flights from 1909. The verb is attested by 1858 in music, 1886 in a non-musical sense. Related: Soloed; soloing.

word-forming element meaning "one who does or makes," also used to indicate adherence to a certain doctrine or custom, from French -iste and directly from Latin -ista (source also of Spanish, Portuguese, Italian -ista), from Greek agent-noun ending -istes, which is from -is-, ending of the stem of verbs in -izein, + agential suffix -tes.

Variant -ister (as in chorister, barrister) is from Old French -istre, on false analogy of ministre. Variant -ista is from Spanish, popularized in American English 1970s by names of Latin-American revolutionary movements.