What is another word for "speculation"?

Roget's Thesaurus (1911) lists these synonyms for "speculation": adventure, aim, analogy, approximation, association, assumed, assumption, attempt, bare, belief, best, blue, bold, chance, conceit, condition, conjecture, coup, dark, data, debut, divination, empirical, endeavor, essay, estimate, exertion, experiment, experimental, experimentally, feel, fortune, grope, guess, guesswork, hand, hard, hint, hypothesis, idea.