This word has distinct meanings in logic, philosophy, and common usage. See connotation.
In semiotics, connotation arises when the denotative relationship between a signifier and its signified is inadequate to serve the needs of the community. A second level of meanings is termed connotative. These meanings are not objective representations of the thing, but new usages produced by the language group.
Drawing from the original definition proposed by Saussure (1857–1913), a sign has two parts:
as a signifier, i.e. it will have a form that a person can see, touch, smell, or hear, and
as the signified, i.e. it will represent an idea or mental construct of a thing rather than the thing itself.
Connotative meanings are developed by the community and do not represent the inherent qualities of the thing or concept originally signified as the meaning. The addition of such meanings introduces complexity into the coding system. If a signifier has only a single denotational meaning, the use of the sign will always be unambiguously decoded by the audience. But connotative meanings are context-dependent, i.e. the addresser must learn how to match the meaning intended by the addresser to one of the various possible meanings held in memory.
The power of connotation is that it enables the addresser to more easily consider abstract concepts and to introduce subtlety into the discourse. For example, a digital thermometer produces a numerical value that indicates the current state of a specific operational parameter. This technology provides an indexical sign of heat (adopting the classification of Charles Sanders Peirce (1839–1914), an indexical sign by real connection between the signifier and the signified). The number is a denotative value, i.e. it speaks only for itself. The doctor, nurse or patient will relate to the number as a visual trope, in this case a metaphor, for the health of the body. Such information adds to other data forming a symptomology for the patient, a summation that takes place at a connotative cognitive level.