Inroad (noun)

An incursion or invasion, especially one that is sudden or unexpected; a penetration or advance into an area or field.

Origin:

From old english inrād ("a raid, incursion, invasion"), from in- ("into") + rād ("a ride, journey, rai.d")

Examples:

1. The enemy made an inroad into the kingdom.
2. The company made an inroad into the market by introducing a new product.
3. The new technology made an inroad into the traditional industry.
4. The disease made an inroad into the population.
5. The company's inroad into the market was met with fierce competition.