| n. | 1. | |
| 1. | A bursting in; a sudden, violent rushing into a place; | |
| 2. | A sudden and violent inroad, or entrance of invaders; |
| Noun | 1. | irruption - a sudden violent entrance; a bursting in; "the recent irruption of bad manners" |
| 2. | irruption - a sudden sharp increase in the relative numbers of a population | |
| 3. | irruption - a sudden violent spontaneous occurrence (usually of some undesirable condition); "the outbreak of hostilities" |