There are a variety of synonyms for the phrase "was expressed by." Some possible options include "was stated by," "was articulated by," "was vocalized by," "was conveyed by," "was pronounced by," "was declared by," "was communicated by," and "was put into words by." These synonyms all convey a sense of someone communicating their thoughts, beliefs, or feelings in a clear and direct manner. Depending on the context, different synonyms may be more appropriate and effective than others. By choosing the right synonym, writers and speakers can convey their intended message with clarity and impact.