Well, actually what you're describing is the definition of connotation.
- From Dictionary.com: the associated or secondary meaning of a word or expression in addition to its explicit or primary meaning: A possible connotation of “home” is “a place of warmth, comfort, and affection.”
- A word's denotation is its reference to the things it designates, its direct, explicit meaning; a word's connotation is things or attributes that the word brings to mind, any idea or notion suggested or associated with the word
So your example sentence could say:
Shakespeare gives the word fair a new and opposite connotation blabla so everytime somebody says fair, it turns out to be foul blabla... After imposing this new connotation on the word fair... succeeding uses of fair show this...
Granted, the connotation of the word fair in the context of Shakespeare's play may not be the same as in the real world, but within the context of the play, Shakespeare is giving fair a new connotation.