1. enter uninvited;

"They intruded on our dinner party"

"She irrupted into our sitting room"

2. erupt or intensify suddenly;

"Unrest erupted in the country"

"Tempers flared at the meeting"

"The crowd irrupted into a burst of patriotism"

3. increase rapidly and in an uncontrolled manner;

"The population of India is exploding"

"The island's rodent population irrupted"