Searching for the semantic boundaries of the Japanese colour term ‘AO’

The Japanese language has a colour term, ‘ao’, which is usually referred to in bilingual dictionaries as being the equivalent of English ‘blue’. Very often, however, it is used to describe things which English speakers would describe as being green. Granny Smith apples are ‘ao’, so are all Westerners ‘ eyes, regardless of whether they would be described as being ‘blue’ or ‘green’ in English. The sky and the sea are prototypically ‘ao’, but this term is also used to describe lawns, forests, traffic lights and unripe tomatoes. What, then, do Japanese native speakers (JNS) understand by this term? How do its semantic boundaries relate to those of the term ‘midori’ (‘green’)? What is the JNS understanding of the foreign loan words ‘guriiri (green) and ‘buruu’ (blue)? This paper reports on ‘ao’ prototypes and prototype theory’s good and bad examples of referents for these four colour terms. It explores, from a semasiological perspective, both the relationships of entailment and the processes of exclusion which operate when JNS select amongst these colour terms. The possibilities and non-possibilities for the shared use of these colour terms are identified for a variety of referents.