By oneself, solitary.
Lacking peers who share one's beliefs, experiences, practices, etc.
Not requiring anything further; merely.
By oneself; apart from, or exclusive of, others; solo.
Without outside help.
Used to emphasize the size or extent of something by selecting a subset.
Not permitting anything further; exclusively.
Done, given, or acting of one's own free will.
Done by design or intention; intentional.
Of or relating to voluntarism.
Endowed with the power of willing.
Working or done without payment.
A supporter of voluntarism; a voluntarist.
A short piece of music, often having improvisation, played on a solo instrument.
A volunteer.