burglar

N. a thief who enters a house or other building by force

The burglar got in the house by breaking the front window.

burglary

N. the act of entering a house or other building by force

There have been so many burglaries in the neighbourhood this year that people are starting to buy big dogs.

burgle

V. to enter a house or other building by force to steal something, to break in

When they got back from their holiday they found that their home had been burgled.

see break in