expectorant /ikspek″tərənt/ [Gk, ex, out, pectus, breast] , 1. pertaining to a substance that promotes the ejection of mucus or other exudates from the lung, bronchi, and trachea. 2. an agent that promotes expectoration by reducing the viscosity of pulmonary secretions or by decreasing the tenacity with which exudates adhere to the lower respiratory tract. Also called mucolytic. Kinds include acetylcysteine, guaifenesin, terpin hydrate. −expectorate, v.
