What does "suffocation" mean?

Suffocation: The act of suffocating, or the state of being suffocated; death caused by smothering or choking. Note: The term suffocation is sometimes employed synonymously with asphyxia. In the strict medico-legal sense it signifies asphyxia induced by obstruction of the respiration otherwise than by direct pressure on the neck (hanging, strangulation) or submersion (drowning). Quain.