To set forth in words; state. To manifest or communicate, as by a gesture; show. See Synonyms at vent1. To make known the feelings or opinions of (oneself), as by statement or art. To convey or suggest a representation of; depict: The painting expresses the rage of war victims. To represent by a sign or a symbol; symbolize: express a fraction as a decimal. To squeeze or press out, as juice from an orange. To send by special messenger or rapid transport: express a package to Los Angeles. Genetics To cause (itself) to produce an effect or a phenotype. Used of a gene: The gene expressed itself under specific environmental conditions. Genetics To manifest the effects of (a gene): Half of the people who inherit the gene express it. Genetics To manifest (a genetic trait): All the mice in the study expressed the defect. Definitely and explicitly stated: their express wish. See Synonyms at explicit. Particular; specific: an express plan. Sent out with or moving at high speed. Direct, rapid, and usually nonstop: express delivery of packages; an express bus. Of, relating to, or appropriate for rapid travel: express lanes on a freeway. By express delivery or transport. A rapid, efficient system for the delivery of goods and mail. Goods and mail conveyed by such a system. A means of transport, such as a train, that travels rapidly and makes few or no stops before its destination. Chiefly British A special messenger. Chiefly British A message delivered by special courier.