Stylistic semasiology

Understatement consists in lessening, reducing the real quan­tity of the object of speech. The psychological essence of under­statement is more complicated than that of hype/bole. The hearer is expected to understand the intentional discrepancy between what the speaker says about the object and what he really thinks about it.
E. g.:
«I was half afraid you had forgotten те».
Litotes is a specific variety of understatement consisting in ex­pressing the lessened degree of quantity of a thing by means of ne­gation of the antonym. The negation of the antonym expresses the positive idea but in a somewhat lessened degree. E. g., «not bad» in the meaning of «good», or «little harm will be done by that».
Litotes. It is based on a peculiar use of negative constructions. The negation plus noun or adjective serves to establish a positive feature in a person or thing. This positive feature is somewhat diminished in quality as compared with a synonymous assertion:
e.g. He is no coward. — He is brave.
Litotes is a deliberate understatement. Here we also observe the direct (negative) meaning and the transferred (affirmative) meaning. It is not a mere denial of the quality, it brings into mind the corresponding antonym, suggesting the presence of the opposite quality.
A variant of litotes is a construction with two negations:
e.g. Her face was not unhandsome.
Litotes is used in different styles of speech excluding the matter-of-fact styles, like official style or scientific prose. In poetry it is sometimes used to suggest that the language fails to adequately convey the poet's feeling:
e.g. "My mistress' eyes are nothing like the sun" (Sonnet 130, W. Shakespeare)
Figures of Quality
Figures of quality, called «tropes» in traditional stylistics, are based on transfer of names.
We must distinguish three types of transfer:

1. 
   transfer by contiguity;
   
2. 
   transfer by similarity;
   
3. 
   transfer by contrast.
   

Transfer by contiguity is based upon some real connection be­tween the two notions: that which is named and the one the name of which is taken for the purpose.
Transfer by similarity is based on similarity, likeness of the two objects, real connection lacking completely.
Transfer by contrast is the use of words and expressions with the opposite meanings — opposite to those meant.
The transfer by contiguity forms the metonymic group of tropes; the transfer by similarity forms the metaphorical group; the transfer by contrast is irony.