/thē-ə-rē/
n. The consensus, idea, plan, story, or set of rules that is currently being used to inform a behavior. This is a generalization and abuse of the technical meaning.
"What's the theory on fixing this TECO loss?"
"What's the theory on dinner tonight?"
("Chinatown, I guess.")
"What's the current theory on letting lusers on during the day?"
"The theory behind this change is to fix the following well-known screw..."