What term refers to a harsh or bitter form of verbal irony?

The term that refers to a harsh or bitter form of verbal irony is sarcasm. Sarcasm involves saying the opposite of what one really means, often in a scornful or mocking tone. It is frequently used to convey contempt or derision, making it distinct from simple irony, which can be more neutral or straightforward.

Satire, while related to irony, is broader in scope as it critiques social norms or human vices, often using humor and exaggeration. Hyperbole refers specifically to exaggerated statements or claims not meant to be taken literally, and it does not inherently convey the sharpness or bitterness associated with sarcasm. A simile is a figure of speech that makes comparisons using "like" or "as" and is unrelated to verbal irony.

Thus, sarcasm stands out as the correct choice due to its specific connotation of biting or harsh criticism wrapped in irony.