Prototype‏ [Noun.]

‘The idea of “the characteristic instance” of a category is know as a prototype. The concept of a prototype helps explain the meaning of certain words, like bird, not in terms of component features (e.g. “has feathers,” “has wings”), but in terms of resemblance to the clearest example. […]

Given the category label furniture, we are quick to recognise chair as a better example than bench or stool. […] However, this is one area where individual experience can lead to substantial variation in interpretation and people may disagree over the categorisation of a word like avocado or tomato as fruit or vegetable.’

– Yule, G. 1985. The Study of Language Cambridge, United Kingdom: Cambridge University Press (2010) p. 119