Pledge short order within time (8)
I believe the answer is:
dedicate
'pledge' is the definition.
(I've seen this in another clue)
'short order within time' is the wordplay.
'short order' becomes 'edic' (I can't justify this - if you can you should give a lot more credence to this answer).
'within' means one lot of letters goes inside another.
'time' becomes 'date' (date is a kind of time).
'edic' going into 'date' is 'DEDICATE'.
Can you help me to learn more?
(Other definitions for dedicate that I've seen before include "Devote, address, to" , "Address (eg, a book to a person)" , "Devote to a sacred person or use" , "Commit" , "Devote (to), pledge (to)" .)