To perform extemporaneously.
To perform without preparation.
To perform without script.
Extemporaneous, impromptu.
Extemporaneously.
At will.
To whatever extent.
At pleasure.
To work as a freelance.
To produce or sell services as a freelance.
A medieval mercenary.
Someone who sells their services to clients without a long-term employment contract.
Of, or relating to a freelance; without employment contract.