(deprive of oxygen and prevent from breathing; "Othello smothered Desdemona with a pillow"; "The child suffocated herself with a plastic bag that the parents had left on the floor")
(impair the respiration of or obstruct the air passage of; "The foul air was slowly suffocating the children")
(be asphyxiated; die from lack of oxygen; "The child suffocated under the pillow")