‖ thalamiumBot.|θəˈleɪmɪəm| [mod.L. dim. of thalamus.] (See quot. 1866.) 1861Bentley Man.Bot. (1870) 375 The body of the apothecium constitutes the thalamium.1866Treas.Bot., Thalamium, a hollow case containing spores in algals; also the disk or lamina prolifera of lichens, and a form of the hymenium in fungals.