Nearly prepared to deliver (4)
I believe the answer is:
read
'deliver' is the definition.
(thesaurus)
'nearly prepared' is the wordplay.
'nearly' means to remove the last letter.
'prepared' becomes 'ready' (associated in meaning).
'ready' with its last letter removed is 'READ'.
'to' acts as a link.
(Other definitions for read that I've seen before include "Interpret writing" , "Measure energy or fuel consumption" , "Absorbed (written text)" , "Study (subject at university)" , "(Of passage) have a certain wording" .)