What is Tac-O?

Tac-O meaning in Military or Military Slang terminology / glossary / dictionary is:
(U.S. Army) Pronounced the same as the dish (taco) , it is another form of Tac, but is generally Used in the absence of the Tactical Officer’s presence. Example: “Hey, have you seen the Tac-O around?”


reference: Glossary of military slang