"To overcome the deficit" means to successfully fill the gap between what is needed or expected and what is actually available or achieved. Full definition
You wonder why we can't overcome a deficit when we don't teach our children correct science? (religion.blogs.cnn.com)
Both state and national initiatives further focus on teacher preparation as a means to overcome the deficits from simple exposure to technology and to promote the actual use of technology in the classroom. (citejournal.org)
In creating its research profile, the Carl Gustav Carus Faculty is also trying to overcome another deficit of clinical research in Germany — the lack of interdisciplinary crossover between medicine and science. (sciencemag.org)