In logic and semantics, connotation is more or less synonymous with intension. Connotation is often contrasted with denotation, which is more or less synonymous with extension. Alternatively, the connotation of the word may be thought of as the set of all its possible referents (as opposed to merely the actual ones). A word's denotation is the collection of things it refers to; its connotation is what it implied about the things it is used to refer to. The denotation of dog is (something like) four-legged canine carnivore. So saying "you are a dog" would imply that you were ugly or aggressive rather than stating that you were canine.
Connotation - Wikipedia, the free encyclopedia