Design is an account of patterns in meaning: the patterns of conventional meaning that are our design resources; the transformation of meaning through designing action that brings into play patterns of differing, where the new meaning draws from available resources for meaning, nevertheless transforming these; and the traces of meaning left in the world that are the residues of design. In an ontology of design, patterns of being (meanings-in) can never be separated from patterns of knowing (meanings-for). This applies to all sentient creatures, ants even. But this is only a matter of degree. Sentient life is the ground of an ontology of design. Then, there is the knowable, in the material structures of nature and society, but which are not yet known. This is where material structures of meaning exceed the ideal, for the moment at least, and perhaps elusively if some remain forever unknowns. And there is the imaginable, where ideal structures of meaning exceed the material, temporarily or forever when the ideal is unrealizable in material reality.