Halliday & Matthiessen (2014: 647-8):
The general sense of hyponymy is ‘be a kind of’, as in ‘fruit is a kind of food’. There is a similar relation in the extending domain (Kinds of lexical relations playing a role in lexical cohesion). This is meronymy – ‘be a part of’. These two lexical relations are contrasted diagrammatically in Figure 9-4: given a lexical set consisting of either hyponyms, where x, y and z are all ‘kinds of’ a, or meronyms, where p, q and r are all ‘parts of’ b.
