Silly to drop right from preliminary document (4)
I believe the answer is:
daft
'silly' is the definition.
(I've seen this before)
'right from preliminary document' is the wordplay.
'right' becomes 'rt'.
'from' suggests deleting specific letters.
'preliminary' becomes 'draft' (I've seen this before).
'document' becomes 't' (I can't justify this - if you can you should believe this answer much more).
'draft' with 'rt' taken out is 'daf'.
'daf'+'t'='DAFT'
'to drop' is the link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for daft that I've seen before include "Potty" , "Informally crazy as a brush" , "Scatty" , "Idiotic" , "Informally silly or crazy" .)