Beginning with an explanation of lexical ambiguity in general, this paper focuses on polysemy. First, it makes a clear distinction between homonymy and polysemy, the two main lexical ambiguity types, to later finish this first section supporting the theory of a lexical ambiguity continuum as proposed by Lyons (1977) and Klepousniotou (2012) among others. The second section focuses on polysemy types, first making reference to the standard account concerning this matter, Alan Cruse’s, and then explaining two other minor theories, those by Andreas Blank and Vyvyan Evans. After talking about polysemy in isolation, information about polysemy in phraseology will be given, based on the paper by Omazić (2008). Later on, an account of theories about sense representation (in the mental lexicon) and access will be given, making reference to the link between them. Among the representation theories, the focus lies on two, the sense enumeration hypothesis and the one representation hypothesis. Even though these two theories are the most important ones, there are some others, especially within literalist approaches: rule-based approaches, the coercion hypothesis and lexical pragmatic approaches. As far as access is concerned, three main theories are given: the ordered search model, the selective (or context-dependent) access model, and the multiple (or exhaustive) access model (Klepousniotou, 2002). After this analysis, some experiments will be provided for and against the two main theories concerning sense representation in the mind. The first one, by Klepousniotou (2002), makes reference to the distinction between homonymy and polysemy in terms of representation in mind. A second experiment will be provided, this time by Beretta et al. (2005), who made a MEG study which ends up providing evidence in favor of the one representation hypothesis. Lastly, an experiment by Klepousniotou et al. is provided, also in favor of the previously mentioned hypothesis. Finally, taking into account that most of the experiments shown are in favor of the one representation hypothesis, this paper will show support for this theory, not without making reference to its limitations.