This is the 780th most frequent Arabic word.
بكثير
"Much" or "by a lot."
The word "بكثير" is used here to emphasize the degree of difference (faster) in a comparative sentence.
هذه السيارة أسرع بكثير من سيارتي.
This car is much faster than my car.
Here, "بكثير" indicates a significant amount of improvement, used to modify the verb.
أداؤه في الامتحان تحسن بكثير عما توقعناه.
His performance in the exam improved much more than we expected.
In this sentence, "بكثير" is used to describe the extent of deliciousness in a comparative context.