Increase dependency? Not Charlie! (8)
I believe the answer is:
addition
'increase' is the definition.
(addition is a kind of increase)
'dependency? not charlie' is the wordplay.
'dependency?' becomes 'addiction' ('addiction' can be a synonym of 'dependency').
'not' is a deletion indicator.
'charlie' becomes 'c' (phonetic alphabet: alpha, bravo, charlie etc.).
'addiction' with 'c' taken out is 'ADDITION'.
(Other definitions for addition that I've seen before include "Mathematical process" , "plus" , "Rider" , "Mathematical procedure" , "Simple kind of arithmetic" .)