Use theories of meaning (UTMs) seem ill-equipped to accommodate the intuition that ignorant but deferential speakers use natural kind terms (e.g. 'zinc') and technical expression (e.g. 'credit default swap') with the same meanings as the experts do. After all, their use deviates from the experts', and if use determines meaning, a deviant use ordinarily would determine a deviant meaning. Yet the intuition is plausible and advocates of UTMs believe it can be accommodated. I examine Gilbert Harman's and Paul Horwich's views, (...) and argue that they do not offer a satisfactory reconciliation of the intuition with the theory. I propose an accommodation based on a novel account of semantic deference, and show that it is consistent with UTMs that a speaker may use a word with a certain meaning without fully or adequately knowing it. (shrink)