1.(of sewage) treated with aeration and bacteria to aid decomposition (Freq. 3) • Similar to: treated 2.(of e.g. a molecule) made reactive or more reactive • Syn: excited • Similar to: reactive • Topics: physics, natural philosophy 3. rendered active; e.g. rendered radioactive or luminescent or photosensitive or conductive • Similar to: active 4.(military) set up and placed on active assignment - a newly activated unit • Similar to: active • Topics: military, armed forces, armed services, military machine, war machine