breakthrough · noun C /ˈbreɪk.θruː/
breakthrough
B2 an important discovery or event that helps to improve a situation or provide an answer to a problem
Dictionary examples:
Scientists are hoping for a breakthrough in the search for a cure for cancer.
A major breakthrough in negotiations has been achieved.
Learner example:
For me the main technology breakthrough has been in computers. (First Certificate in English; B2; Catalan)