tentative

Short definition from Wiktionary

Noun

1. 1
   A trial; an experiment; an attempt.
2. 2
   A schedule for an event or a programme.

Adjective

1. 1
   Of or pertaining to a trial or trials; essaying; experimental.
2. 2
   Uncertain; subject to future change.
3. 3
   Restrained; polite; feeling one's way, not using full force.