have a somewhat strange strange question. Here it goes. You know how in a long poem or novel, an author might use slightly different words that refer to the same thing in different context.Do you know of any studies that address how this author chooses the words in order to suit the context (preferably this has to be subtle).
I'll make up an example so that you might know what I am talking about (excuse its childishness)
For example, "The boy went to the fetch some water.... The lad came to the fighting match"
The word lad was used in the second sentence instead of boy although it refers to the same person because lad reminds the readers of Scotland and Scots are famous for their bravery and fighting matches require bravery.

I assume there is a lot of research of these things within literary studies. But more closely associated with linguistics would be work on authorship, especially within computational linguistics and forensic linguistics. That might interest you.