1. (

• engine

) motor that converts thermal energy to mechanical work ;

2. (

• engine

) something used to achieve a purpose; "an engine of change" ;

3. (

• locomotive ,
• engine ,
• locomotive_engine ,
• railway_locomotive

) a wheeled vehicle consisting of a self-propelled engine that is used to draw trains along railway tracks ;

4. (

• engine ,

) an instrument or machine that is used in warfare, such as a battering ram, catapult, artillery piece, etc.; "medieval engines of war" ;