Take no notice in revealing design or expression (6)
I believe the answer is:
ignore
'take no notice' is the definition.
(I've seen this before)
'revealing design or expression' is the wordplay.
'revealing' indicates the answer is hidden within the clue (I've seen this in other clues).
'IGNORE' is hidden in the letters of 'design or expression'.
'in' acts as a link.
(Other definitions for ignore that I've seen before include "Refuse to notice or acknowledge" , "Brush off" , "Dismiss" , "Walk away from" , "Blank" .)