Vastness is a word that relates to something large or immense in size, extent, or quantity. There are several synonyms of vastness that can be used to describe the same meaning, including enormity, magnitude, immensity, greatness, expansiveness, and hugeness. Enormity refers to something that is enormously large, while magnitude is often used when talking about something that is measured in size or quantity. Immensity is a word that conveys the meaning of being vast or huge, while greatness describes something that is of remarkable size or significance. Expansiveness and hugeness are words that are commonly used to describe something that is extremely large or broad in scope.