Within the field of phraseology, phrasemes are recognized as being semantically more complex than single words (Burger 2007: 79). The polysemy and ambiguity of idioms, their semantic approximation and the added value, their wide meaning, and their context-dependence has led many researchers to acknowledge that preparing “a range of semems” from the wider meaning of the idiomatic units in which they are used is problematic (Fleischer 1997: 168). This belief has marginalized the debate about the boundaries between meanings and their variants. In linguistics, studies based on language use and cognitive approaches are playing an increasingly important role, and there has been a “corpus revolution” in phraseography. This means that lexical ambiguity, polysemy and vagueness have gained greater relevance. In phraseology, developing the capture and description of idiomatic meaning cannot be achieved without a theoretical discussion of “the wide meaning”. The aim of this study is to explore a selection of the problems facing linguists when they try to capture meaning and describe phrasemes from a cognitive perspective. The study will focus on questions of ambiguity, polysemy and vagueness, and their impact on the theory and practice of phraseology and phraseography.