solo (Noun) — Any activity that is performed alone without assistance.
solo (Noun) — A musical composition for one voice or instrument (with or without accompaniment).
solo (Noun) — A flight in which the aircraft pilot is unaccompanied.
solo (Adjective) — (music) composed or performed by a single voice or instrument. ex. "a passage for solo clarinet"
solo (Verb) — (air travel) fly alone, without a co-pilot or passengers.
solo (Verb) — Perform a piece written for a single instrument.
solo (Adverb) — Without anybody else or anything else. ex. "he flew solo"