Definition of probationist:
(n) :
A period of time when a person occupies a position only conditionally and may be removed if certain conditions are not met.
(n) :
(law) A type of sentence where convicted criminals are permitted to continue living in a community but will automatically be sent to jail if they violate certain conditions.
(n) :
A testing period of time.
(n) :
(archaic) The act of testing; proof.