Promise the return of some imprisoned rowdies (4)
I believe the answer is:
word
'promise' is the definition.
(as in 'I give you my word')
'return of some imprisoned rowdies' is the wordplay.
'return of' is a reversal indicator.
'some' indicates a hidden word (some parts of the word are used).
'drow' is hidden within 'imprisoned rowdies'.
'drow' back-to-front is 'WORD'.
'the' is the link.
(Other definitions for word that I've seen before include "Puzzle with solutions reading the same down as across" , "Promise; news" , "usually comes with more than one letter" , "Element of language" , "Term" .)