Comparison between two far-fetched objects of different kind is called -

Epigram: An epigram is a short but insightful statement, often in verse form, which communicates a thought in a witty, paradoxical, or funny way.
Example
- I can resist everything but temptation

Conceit: Comparison between two far-fetched objects of different kind. It is a figure of speech, usually a simile or metaphor, that forms an extremely ingenious or fanciful parallel between apparently dissimilar or incongruous objects or situations.

Connotation: The indirect meaning of a word. It is the suggestion or associated significance implied by a word.
Example
- Home is the place where, when you have to go there,
- They have to take you in.

Epic Simile: An open comparison between two dissimilar objects of which one is fairly elaborated. As the epic poets introduced this term, it is called Epic simile.

Source- An ABC of english Literature, Dr. M Mofizur Rahman