A definition of metonymy that has gained some popularity in Cognitive Linguistics contrasts metonymical semantic shifts within a domain or domain matrix with metaphorical shifts that cross domain boundaries. In the past few years, however, this definition of metonymy has become subject to more and more criticism, in the sense that it relies too much on the vague notions of domains or domain matrices to be fully reliable. In this article, we address this problem by focusing on a nonunitary, prototypical definition of contiguity (the concept that used to be seen as the defining feature of metonymy before Cognitive Linguistics introduced domains and domain matrices). On the basis of the traditional pre-structuralist literature on metonymy, we identify a large number of typical metonymical patterns, and show that they can be classified in terms of the type of contiguity they are motivated by. We argue that metonymies, starting from spatial part-whole contiguity as the core of the category, can be plotted against three dimensions: strength of contact (going from part-whole containment over physical contact to adjacency without contact), boundedness (involving an extension of the part-whole relatinoship towards unbounded wholes and parts), and domain (with shifts from the spatial to the temporal, the spatio-temporal and the categorical domain).