Intensional adjectives are adjectives like former and possible, which, in constructions like former president and possible candidate, cannot be interpreted as sets of entities that are 'former' or 'possible', as would be the case with extensional adjectives like red. The phrase the former president does not denote the individual that is both a president and 'former', but it denotes the individual that was president in a preceding term. In this way intensional adjectives manipulate the temporal or modal parameter that is relevant for the interpretation of the nouns they combine with.
- Chierchia and McConnell-Ginet 1990. Meaning and grammar, MIT Press, Cambridge, Mass.