The term elephant test refers to situations in which an idea or thing ‘is hard to describe, but instantly recognizable when spotted.’ The term is often used in legal cases when there is an issue which may be open to interpretation, such as in the case of Cadogan Estates Ltd v Morris, when Lord Justice Stuart-Smith referred to ‘the well known elephant test. It is difficult to describe, but you know it when you see it.’
The Daily Omnivore 