The emotional response evoked by a word or the associations called up by a word that goes beyond its dictionary meaning.
Dylan Thomas's "Do Not Go Gentle into That Good Night" includes intensely connotative language, as in these lines:
Do not go gentle into that good night,
Old age should burn and rave at close of day;
Rage, rage against the dying of the light.
[n] an idea that is implied or suggested
[n] what you must know in order to determine the reference of an expression