Sponger coming first in list flipped (5)
I believe the answer is:
leech
'sponger' is the definition.
(I know that sponger can be written as leech)
'coming first in list flipped' is the wordplay.
'coming first' becomes 'c' (1st letter of 'coming').
'in' indicates putting letters inside.
'list' becomes 'heel' (both can mean to lean or tilt).
'flipped' is a reversal indicator.
'c' placed inside 'heel' is 'hceel'.
'hceel' in reverse letter order is 'LEECH'.
(Other definitions for leech that I've seen before include "Blood-sucking creature" , "Annelid worm, used in medicine of old" , "One used to bleed" , "One who sponges on others" , "Small worm once used for blood-letting, or a parasitical person" .)