Full Idea
A definition is 'extensionally adequate' iff there are no actual counterexamples to it. It is 'intensionally adequate' iff there are no possible counterexamples to it. It is 'sense adequate' (or 'analytic') iff it endows the term with the right sense.
Gist of Idea
A definition can be 'extensionally', 'intensionally' or 'sense' adequate
Source
Anil Gupta (Definitions [2008], 1.4)
Book Reference
'Stanford Online Encyclopaedia of Philosophy', ed/tr. Stanford University [plato.stanford.edu], p.5