1) Cautious 2) Conditional 3) French word used in English 4) Full of hedges 5) Hesitant, cautious 6) Not carved in stone 7) Not definite yet 8) Not final 9) Not fully worked out 10) Only penciled in 11) Probationary 12) Provisional 13) Provisionary 14) Uncertain 15) Unsettled in mind or opinion 16) Up in the air Found on https://www.crosswordclues.com/clue/tentative
Ten·ta'tive adjective [ Latin tentare to try: confer French tentatif . See Tempt .] Of or pertaining to a trial or trials; essaying; experimental. 'A slow, tentative manner.' Carlyle. -- Ten*ta'tive*ly , adverb Found on http://www.encyclo.co.uk/webster/T/27