'break-in' definitions:

Definition of 'break-in'

From: WordNet
noun
Trespassing for an unlawful purpose; illegal entrance into premises with criminal intent [syn: housebreaking, break-in, breaking and entering]

Definition of 'break-in'

From: GCIDE
  • break-in \break-in\ n. an act of trespassing into a closed structure such as a house or place of busineess for an unlawful purpose, usually as part of a burglary.
  • Syn: housebreaking, breaking and entering. [WordNet 1.5 +PJC]