1.
rejection reaction (medical); transplant rejection
The immune system's response when rejecting transplanted organs or tissue.
2.
strong aversion; visceral rejection; instinctive resistance
A figurative extension of the medical meaning, describing an intense, almost physical feeling of rejection toward an idea, person, or situation.
Usage
拒絶反応 originally refers to the medical phenomenon of transplant rejection, but is widely used figuratively to describe a visceral, almost physical feeling of rejection or aversion. The figurative use is very common in everyday conversation.