Short time (6)
'short time' is the definition.
(second is a kind of short time)
This is the entire clue.
(Other definitions for second that I've seen before include "A boxer's corner assistant - not the first" , "Time for a supporter" , "Position of runner-up" , "Attendant in a duel or boxing match" , "Silver medal position" .)
'short time' is the definition.
(short for second)
This is all the clue.
(Other definitions for sec that I've seen before include "very short space of time" , "Twinkling" , "Dry wine perhaps" , "'Dry, as wine (3)'" , "Mo or min?" .)