Scary colleague in Shoreditch so psyched up (4)
I believe the answer is:
posh
'scary colleague' is the definition.
(I know that Posh is a colleague of Melanie Brown)
'in shoreditch so psyched up' is the wordplay.
'in' indicates the answer is hidden within the clue.
'up' shows that the letters should be reversed in order (in down clue: letters go upwards).
'hsop' is hidden within 'shoreditch so psyched'.
'hsop' in reverse letter order is 'POSH'.
(Other definitions for posh that I've seen before include "Mrs 4 across (colloq.)" , "Of the wealthy classes" , "U" , "This 13 [SPICE]" , "Swanky" .)