Abstract
This paper analyzes the semantic properties of the Spanish adverb más o menos 'about, more or less'. This adverb has been conceived as an approximative adverb, similarly to other, more prototypical forms, like almost or barely. Nevertheless, the propositional implications of almost and barely do not arise in más o menos, due to its particulary vague status. While almost and barely present a proximity-polarity pattern, más o menos implies an inconsistency of presuppositions, yielding differing readings. For this reason, I classify adverbs like más o menos as approximators, in opposition to adverbs like almost and barely, which have been classified as approximatives. Semantically, both types of adverbs can be considered to be vagueifier items; however, while almost and barely have scope over negation, más o menos introduces a series of more complex relations connected to the problem of higher-order vagueness.