Stick present under notice (6)
I believe the answer is:
adhere
'stick' is the definition.
('adhere' can be a synonym of 'stick')
'present under notice' is the wordplay.
'present' becomes 'here' ('here' can be similar in meaning to 'present').
'under' means one lot of letters go next to another.
'notice' becomes 'ad'.
'here' after 'ad' is 'ADHERE'.
(Other definitions for adhere that I've seen before include "Stick to, remain loyal" , "Stick to as by suction" , "Cling, attach" , "Stick to or continue faithful" , "Stay attached" .)