Very (4)
'very' is the definition.
(synonyms)
This is the entire clue.
(Other definitions for much that I've seen before include "To a great extent" , "A lot of unnecessary fuss" , "Great quantity" , "Chum (anag.)" , "A great deal" .)
(Another definition for well and truly that I've seen is " completely".)
'very' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for extremely that I've seen before include "remarkably" , "To a high degree or extent" .)