Incursion (noun)

1. An invasion or attack, especially one made by a military force.
2. A sudden, usually brief, entry into a place or sphere of activity.

Origin:

Late 16th century, from the latin incursiōnem, meaning "an attack," from incursus, meaning "a running into, a charge," past participle of incurrere, meaning "to run into, charge.".

Examples:

1. The enemy launched a sudden incursion into the country.
2. The incursion of technology into the classroom has changed the way students learn.
3. The company made a successful incursion into the cosmetics market.
4. The police made an incursion into the gang's hideout.
5. The incursion of the hunters into the forest caused the animals to flee.