Has to remove third note, silent (4)
I believe the answer is:
mute
'silent' is the definition.
(I know that silent can be written as mute)
'has to remove third note' is the wordplay.
'has' becomes 'ut' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'to' says to put letters next to each other (I've seen this in other clues).
'remove third' becomes 'm' (3rd letter of 'remove').
'note' becomes 'e' (musical note).
'ut' after 'm' is 'mut'.
'mut'+'e'='MUTE'
Can you help me to learn more?
(Other definitions for mute that I've seen before include "Silent - dumb" , "Silent or speechless" , "Silent, refraining from speaking" , "Deaden sound of" , "Speechless, soundless" .)