tertiary
adj
third in order, rank, importance, etc; next after secondary 第三等的; 第三位的; 第三的
the Tertiary period, ie (in geology) the third stage in the formation of rocks (地质学上岩石形成的)第三纪
tertiary education, ie at university or college level 高等教育
tertiary (ie very severe) burns 三度烧伤(极严重的).