adjective Characterized by major progress or overcoming some obstacle.
a breakthrough technological advance
adjective 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.
noun An advance through and past enemy lines.
noun 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.
noun The penetration of the opposition's defence.
noun 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.
noun 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.