athermanous,a.Physics.|əˈθɜːmənəs|[f.Gr.ἀpriv.+ θερµαν- stem of θερµαίν-ειν to heat (f.θέρµη heat) + -ous.]Not permeable by radiant heat.1863TyndallHeat iii. 79An athermanous body which stops the radiation.
1871B. StewartHeat §206This substance is..athermanous, that is to say opaque for heat.