This paper explores the semantics of system design terminology with the purpose of facilitating communication during the design process. Entities, agents and systems are described by nouns. Activities, functions and processes are described by verbs. A system (noun) can only be designed by specifying its characteristics - adjectives - in a quantitative way. Give the engineer a number! Systems by themselves are inert. It is only when they interact with other systems that a purposeful process occurs. Processes are described by verbs and quantified (qualified) by adverbs. These ideas are pursued with examples from automobile design and the development of space systems.