Vary (6)
'vary' is the definition.
(I know that vary is a kind of diversify)
This is all the clue.
(Other definitions for alter that I've seen before include "and 10 Across: Second self" , "convert" , "Change, modify" , "Change or adjust" , "shift" .)
'vary' is the definition.
(I know that vary is a kind of differ)
This is the entire clue.
(Other definitions for differ that I've seen before include "Disagree or vary" , "Be at variance (with)" , "quarrel" , "Disagree, take issue" , "Disagree or vay" .)