Analysts using the Metaphor Identification Procedure (MIP/MIPVU) (Pragglejaz Group, 2007; Steen, et al., 2010) are dependent on a dictionary when deciding what counts as a metaphor in natural discourse. This paper investigates the role of the dictionary in metaphor identification. A 50,000 word corpus of French newspaper texts was analyzed with two dictionaries: Le Petit Robert (Rey-Debove, 2009) and Le Grand Robert & Collins (Durand, 2009). The findings show that metaphor identification is slightly more straightforward for function words (e.g. prepositions) than for content words (e.g. verbs). The results are studied quantitatively by measuring agreement between the two dictionaries and qualitatively by investigating difficulties in more detail. This paper also sets forth how analysts can use dictionaries in a pragmatic way without detracting from the improved reliability and reproducibility of the method.