Etymologically, a [[metaphor]] "carries across" from one domain to another. It locates a similarity across two different domains.
[[metonymy|Metonymy]], by contrast, “operates *within* an idealized cognitive model” ([[Radden et al 2014 - Towards a Theory of Metonymy|18]]; my emphasis). That is, it operates within a single domain
This is congruent with [[Ronald Langacker]]'s idea that metonymy is a [[Langacker 1993 - Reference-Point Constructions|reference-point phenomenon]]. Metonymy is a "reference-point" that provides access to a "target" within the same domain:
![[langacker_metonymy_reference_point_figure_1.png]]