Noun
1. any activity that is performed alone without assistance
2. a musical composition for one voice or instrument (with or without accompaniment)
3. a flight in which the aircraft pilot is unaccompanied
Verb
1. fly alone, without a co-pilot or passengers
2. perform a piece written for a single instrument
Adjective
1. composed or performed by a single voice or instrument;
"a passage for solo clarinet"Adverb
1. without anybody else;
"the child stayed home alone""he flew solo"