Spoken to without notice to be prepared (7)
I believe the answer is:
dressed
'prepared' is the definition.
(dressing is a kind of preparing)
'spoken to without notice' is the wordplay.
'spoken to' becomes 'addressed' ('address' can be a synonym of 'speak to').
'without' indicates named letters should be taken away.
'notice' becomes 'ad' (both can mean an advertisement).
'addressed' with 'ad' taken away is 'DRESSED'.
'to be' is the link.
(Other definitions for dressed that I've seen before include "Up and ready to go" , "with mayonnaise, say" , "put bandage on" , "Brought into line" , "Trimmed" .)