Pressing uniform finally for chap (6)
I believe the answer is:
urgent
'pressing' is the definition.
(I know that pressing can be written as urgent)
'uniform finally for chap' is the wordplay.
'uniform' becomes 'U' (phonetic alphabet: alpha, bravo, charlie etc.).
'finally' indicates one should take the final letters.
'chap' becomes 'gent' (I've seen this in other clues).
The final letter of 'for' is 'r'.
'u'+'r'+'gent'='URGENT'
(Other definitions for urgent that I've seen before include "Pressing, burning" , "Needing early action" , "demanding speedy action" , "Earnest, insistent" , "Important and in a hurry" .)