Denotations and connotations:

In simplistic definition, it is the secondary meaning of a word.
E.g. Red is a colour: This colour is associated with evil, danger, high temperature AKA heat.
That was a connotation, a denotation is the direct meaning or set f meanings based on a word or an expression.
E.g. an angry face is assocaited with something going bad, or an event damaging that person's feelings.
E.g. Poodle is a denotation of a breeded dog.