Ex hypothesi: According to assumptions, based on assumptions. (New Latin ex hypothesi : Latin ex, out of, by + Latin hypothesi, ablative of hypothesis, hypothesis)

Hypothesis is a guess a theory is an answer

There is no past tense, it's a noun. So it is hypothesis. The plural form is hypothesi. 2nd Answer: . . . the commonly used plural, though, is hypotheses.

The quantum theory of multi-state subatomic particle transubstantiation as applied during empirical testing of the fermentation of locally acquired yeasts and their effect on the creation of possible titles of hypothesi

Francesco Redi's hypothesis was that "spontaneous generation" could not exist. He tested this hypothesis using maggots and meat.