Stick a note in this place (6)
I believe the answer is:
adhere
'stick' is the definition.
('adhere' can be a synonym of 'stick')
'a note in this place' is the wordplay.
'note' becomes 'd' (musical note).
'in this place' becomes 'here' ('here' can be a synonym of 'in this place').
'a'+'d'+'here'='ADHERE'
(Other definitions for adhere that I've seen before include "Stick firmly" , "Agree" , "Stick L" , "Stick or cleave to" , "Stick to - cement" .)