The paper presents a domain ontology service as an enabling component of the semantic Web. A domain ontology service is a shared, distributed knowledge-base allowing terms (as strings) to be assigned a precise meaning wrt to a category ontology. A domain ontology service can be used by a range of semantic Web applications, such as yellow-page catalogs or by IR search engines to refine or disambiguate querys terms. A more complex application of a domain ontology service is to perform subsumption-based inference and perform knowledge-based search and generalization. 1 Introduction One assumption of the"semantic Web" is that knowledge producers will generate knowledge (as metadata or content descriptors) that is comparable. When you or I use the term "switch", a domain ontology service locally proposes various meanings of "switch": (i) a mechanical, electrical device; (ii) a flexible instrument for punishment; (iii) a subsitute (iv) a basketball maneuver, etc. Term refinement..