Initially this is generally held to close (5)
I believe the answer is:
tight
'close' is the definition.
(I know that close can be written as tight)
'initially this is generally held to' is the wordplay.
'initially' says to take the initial letters.
The first letters of 'this is generally held to' is 'TIGHT'.
(Other definitions for tight that I've seen before include "with limited room to manoeuvre" , "Miserly or blotto" , "Hard to move; drunk" , "Strictly imposed; drunk" , "Tense; secretive" .)