There are numerous synonyms that can replace the phrase "looks big," depending on the context. Some synonyms for looks big might include: appears substantial, seems sizeable, seems voluminous, looks extensive, looks expansive, looks generous, appears ample, looks roomy, appears spacious, and looks substantial. These words can be used to describe anything from objects to buildings, to people or animals. For example, when describing an elephant, one might say it appears substantial or voluminous, whereas when describing a house, one might say it seems expansive or spacious. Regardless of the scenario, there is always a fitting word to replace "looks big.