tentative vs probationary

tentative and probationary both are adjectives.

Word	Noun	Adjective	Verb	Adverb
tentative	No	Yes	No	No
probationary	No	Yes	No	No

As adjectives, tentative and probationary are synonyms defined as:

tentative and probationary: under terms not final or fully worked out or agreed upon

Other synonyms of tentative include provisional, provisionary.

tentative (adjective)	probationary (adjective)
under terms not final or fully worked out or agreed upon	under terms not final or fully worked out or agreed upon
unsettled in mind or opinion