Way a little torpedo moves backwards (4)
I believe the answer is:
mode
'way' is the definition.
(I know this)
'a little torpedo moves backwards' is the wordplay.
'a little' indicates the answer is hidden within the clue.
'backwards' is a reversal indicator.
'edom' can be found hidden inside 'torpedo moves'.
'edom' reversed gives 'MODE'.
(Other definitions for mode that I've seen before include "Style (of clothes, etc)" , "Fashion; way of performing" , "Manner of dome" , "Manner, style" , "Trend" .)