In fear I seriously reveal part of step (5)
I believe the answer is:
riser
'part of step' is the definition.
('riser' is part of 'step')
'in fear i seriously' is the wordplay.
'in' says the answer is hidden in the clue.
'RISER' can be found hidden inside 'fear i seriously'.
'reveal' is the link.
(Other definitions for riser that I've seen before include "He gets up" , "Bit of a step up?" , "Stair front" , "Vertical pipe in a building" , "Vertical part of a stair or step" .)