Explanation at beginning of article sounds strange (6)
I believe the answer is:
theory
'explanation' is the definition.
(I know that theory is a type of explanation)
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for theory that I've seen before include "The words, as opposed to the practice" , "Scientific conjecture" , "Guess" , "Scientific supposition" , "Proposed explanation of something" .)