NCIt definition : An involuntary contraction of the diaphragm against closed vocal cords, producing
the hic sound.;
Alternative definition : CTCAE: A disorder characterized by repeated gulp sounds that result from an involuntary
opening and closing of the glottis. This is attributed to a spasm of the diaphragm.; FDA: An involuntary contraction of the diaphragm against closed vocal cords, producing
the hic sound.;