The term expectorant refers to therapeutic agents (e.g. natural substances
such as herbs, oils, or essences, or conventional pharmaceutical drugs)
that help to ease the removal of mucus from the respiratory system.
In more medical parlance, expectorants are (usually) drugs that aid
and increase the secretion of sputum by the air passages in the respiratory
so that it is easier for the person to cough up to expel excessive
Expectorants are commonly included in cough mixtures
and cold/flu remedies. This term is therefore familiar to many people
as it appears on the packaging of popular medications that are widely
available without prescription.