We examine the strategies of organizing terminological information in WordNet, and describe an analogous strategy of adding terminological senses of lexical units to plWordNet, a large Polish wordnet. Wordnet builders must cope with differences in lexical and terminological definitions of a term, and with the boundaries between terminological and lexical information. A somewhat adjusted strategy is required for Polish, though both WordNet and plWordNet rely mainly on semantic relations in organizing the terminological and general-language units. The proposed guidelines for plWordNet, built on several distinct combinations of denotation and connotation, have a solid theoretical underpinning but will require a large-scale verification of their effectiveness in practice.