Answer: Depends on what your talking about so I'll give all 3 definitions. 
Explanation:
1.)The literal or primary meaning of a word, in contrast to the feelings or ideas that the word suggests. 
-Used in a sentence- Beyond their immediate denotation, the words have a connotative power.
2.) When used in philosophy it means, the object or concept to which a term refers, or the set of objects of which a predicate is true. 
3.) And, the last definition is, the action or process of indicating or referring to something by means of a word, symbol, etc.