What is another word for "tentative"?

Roget's Thesaurus (1911) lists these synonyms for "tentative": adventure, aim, attempt, best, bold, chance, coup, debut, empirical, endeavor, essay, exertion, experiment, experimental, experimentally, feel, fortune, grope, hand, hard, luck, make, may, non, one, pick, probation, probationary, push, rule, speculate, speculation, strive, struggle, take, tempt, thumb, trial, try, use.