A versatile word, solo means "alone" and can be used as a verb ("I get to solo in band today"), a noun ("She sang a beautiful solo"), or an adjective (I can't wait for my solo flight").
The word solo is often associated with a musical performance, from the Italian derivative from the Latin sōlum, "alone." Until the end of the 17th century, just the Latin form was used, usually in stage directions. Then it entered musical terminology, as sola, in 1695. The adjectival use developed in the 18th century, and in 1864 the form soloist, referring to one who performed a solo, first appeared. It wasn't until the mid-19th century that the word was used as a verb.