Edition of new revision lacking one (7)
I believe the answer is:
version
'edition' is the definition.
(I know that edition can be written as version)
'new revision lacking one' is the wordplay.
'new' indicates an anagram.
'lacking' is a deletion indicator.
'one' becomes 'i' (Roman numeral).
'revision' with 'i' removed is 'revsion'.
'revsion' with letters rearranged gives 'VERSION'.
'of' acts as a link.
(Other definitions for version that I've seen before include "Adaptation" , "Something a little different - so riven (anag)" , "Rendering" , "Particular form (of something)" , "Model" .)