1. relating to or based on the extension or scope of a term; concerned with the actual objects or instances that a word refers to rather than its meaning or properties
Usage: logic and philosophy; formal/technical
2. of or relating to extension in space; capable of being extended
Usage: rare; formal

Examples

• In logic, an extensional definition lists the actual members of a set rather than describing their properties.
• The extensional meaning of 'planet' includes Earth, Mars, Venus, and all other celestial bodies that fit the definition.
• Philosophers debate whether language is best understood in extensional or intensional terms.
• Two terms may have the same extensional reference but different intensional meanings.
• The extensional approach focuses on what things are rather than how we describe them.