This chapter examines the relationship between metonymy and cases of category broadening and narrowing and the resulting state of vertical polysemy (e.g., cat domestic cat > any feline and drink consume liquid > consume alcohol). Broadening and narrowing have been argued to be motivated by metonymic processes where a category member stands for the whole category or vice versa (Radden and Kvecses, 1999; cf. also Lakoff, 1987). Here, I show that there is a crucial difference between the domain structures involved in metonymy and in vertical polysemy. Unlike metonymies, broadening and narrowing do not involve a shift in the salience of domains (see Croft, 1993). Instead, I argue that there are four possible domain configurations that may underlie vertically related meanings.