The definition of momentous is an important moment or something important.
An example of momentous as an adjective is a momentous wedding, an important event in someones life.
Of utmost importance; of outstanding significance or consequence: a momentous occasion; a momentous decision.
- I waited until evening to make my momentous call to Agent Brennan.
- It is noticeable that, while he held his office in the curia through that momentous period of fifty years which witnessed the Councils of Constance and of Basel, and the final restoration of the papacy under Nicholas V., his sympathies were never attracted to ecclesiastical affairs.
- The consequences of this blow were momentous; it may be said to inaugurate the ghetto period.
- His experiments, in the same year, on the photographic registration of stellar spectra, marked an innovation of a momentous character.
- The momentous question was discussed at a meeting of the opponents of the Vatican decrees, and it was resolved to elect a bishop and ask the Dutch bishops to consecrate him.