Sneak lied about following second (5)
I believe the answer is:
sidle
'sneak' is the definition.
(I've seen this in another clue)
'lied about following second' is the wordplay.
'about' indicates an anagram.
'following' means one lot of letters go next to another.
'second' becomes 's' (common abbreviation).
'lied' with letters rearranged gives 'idle'.
'idle' after 's' is 'SIDLE'.
(Other definitions for sidle that I've seen before include "Inch along" , "Move along sideways" , "Move in furtive manner, edge along" , "Isled (anag.)" , "Move like a crab" .)