Deliberately avoid or ignore (4)
I believe the answer is:
shun
I believe this clue is a double definition.
'deliberately avoid' is the first definition.
(I've seen this before)
'ignore' is the second definition.
(I've seen this before)
(Other definitions for shun that I've seen before include "rigid standing order?" , "Cold-shoulder" , "Avoid, ignore" , "Persistently avoid" , "Avoid contact" .)