Reporters appearing in Ypres slowly (5)
I believe the answer is:
press
'reporters' is the definition.
(newspaper reporters)
'in ypres slowly' is the wordplay.
'in' indicates a hidden word.
'PRESS' is hidden in the letters of 'ypres slowly'.
'appearing' acts as a link.
(Other definitions for press that I've seen before include "harass > crowd" , "Enlist crew" , "Jam" , "publicity" , "Squeeze out (juice/oil)" .)