The phrase "be big" refers to something or someone that is large, important, or impressive. Synonyms for this phrase include "towering", "colossal", "majestic", "massive", "monumental", "grandiose", "super-sized", "gigantic", "immense", "enormous", "vast", "stupendous", "heroic", "king-sized" and "oversized". When we use any of these synonyms, we are describing something of great size or significance that commands attention. The choice of synonym depends on the context and the specific emphasis we want to convey about the aspect of bigness we want to highlight. Whatever word we choose, it is clear that we are talking about something or someone that is substantial and worthy of notice.