breakthrough

adj

1. (not-comparable)Characterized by major progress or overcoming some obstacle.

   “a breakthrough technological advance”

2. (not-comparable)Involving the contraction of a disease by a person with a decreased susceptibility, such as a person who has been vaccinated to help prevent that disease.

   “Breakthrough infections (urine infections that develop in children on antibiotics) can occasionally occur, and if they do, different preventative antibiotics can be given or sometimes surgery to fix the leaky valve can be undertaken.”

   “There is also growing evidence that while Omicron may cause many breakthrough cases among previously infected or previously vaccinated populations, the morbidity and mortality associated with the disease among them will be lower, they added.”

noun

1. An advance through and past enemy lines.
2. Any major progress; such as a great innovation or discovery that overcomes a significant obstacle.

   “Albert Einstein is credited with making some of the greatest breakthroughs in modern physics.”

   “In [Raymond] Kurzweil’s future, biotechnology and nanotechnology give us the power to manipulate our bodies and the world around us at will, at the molecular level. Progress hyperaccelerates, and every hour brings a century’s worth of scientific breakthroughs.”

   “"Secondly, we have to find more cost-effective ways of electrifying. And we've had a real breakthrough in the last couple of years in terms of bridge clearances and immunisation, meaning we've been able to take hundreds of millions of pounds off the cost of electrification.”

3. The penetration of the opposition's defence.

   “But with the lively Dos Santos pulling the strings behind strikers Pavlyuchenko and Defoe, Spurs controlled the first half without finding the breakthrough their dominance deserved.”

4. The penetration of a separating wall or the remaining distance to an adjacent hollow (a crosscut in mining) or between two parts of a tunnel build from both ends.
5. (attributive, sometimes)The emergence or one or more symptoms of a condition despite medication or other medical treatment.

   “She was on two antiepileptics for five years but then had a breakthrough seizure.”

   “He was managing his discomfort with common painkillers, but one morning he had breakthrough pain causing him to miss work.”