Fast, like the one-step (5)
I believe the answer is:
apace
'fast' is the definition.
('apace' can be a synonym of 'fast')
'the one-step' is the wordplay.
'the one' becomes 'a'.
'step' becomes 'pace' ('pace' can be a synonym of 'step'**).
'a'+'pace'='APACE'
'like' is the link.
(Other definitions for apace that I've seen before include "At a rapid rate" , "fast" , "Quick" , "What's quickly" , "(Move on) swiftly" .)