This paper investigates how the semantic structure of one English word depends on, and reflects, our models of relevant areas of experience. As a linguist, my original concern was with the problems posed by the word lie for traditional semantic theories; but these problems led inexorably to the cultural models of informational exchange that motivate the existence of a semantic entity meaning lie. I begin by posing the semantic problem and go on to the cultural solution. George Lakoff (1972), Fillmore (1977), and Coleman and Kay (1981) have argued against traditional generative and structuralist “checklists” of semantic features that constitute necessary and sufficient conditions for set-membership in the category denoted by a word. Lexical categories can have better or worse members, or partial members. Kay and McDaniel (1978) have shown that color categories lack necessary and sufficient conditions; red is a gradient quality whose category–boundaries are best described by fuzzy set theory rather than by traditional set theory. Checklist feature–definitions, which do not allow for color's being “sorta red,” must be replaced by a theory capable of dealing with fuzzy set–membership. Prototype semantics views word–meaning as determined by a central or prototypical application, rather than a category–boundaries. Clear definitions can thus be given for words with fuzzy boundaries of application. We define the best instance of a word's use, and expect real-world cases to fit this best example more or less, rather than perfectly or not at all.