Thal"lous (?), a. (Chem.) Of or pertaining to thallium; derived from, or containing, thallium; specifically, designating those compounds in which the element has a lower valence as contrasted with the thallic compounds. [Written also thallious.]

Thal"lous (?), a. (Chem.) Of or pertaining to thallium; derived from, or containing, thallium; specifically, designating those compounds in which the element has a lower valence as contrasted with the thallic compounds. [Written also thallious.]