Maybe vampire conceals one lure (4)
I believe the answer is:
bait
'one lure' is the definition.
(synonyms)
'maybe vampire conceals' is the wordplay.
'maybe' becomes 'i' (I've seen this in other clues).
'vampire' becomes 'bat' (vampire bat).
'conceals' indicates putting letters inside.
'i' inserted inside 'bat' is 'BAIT'.
(Other definitions for bait that I've seen before include "Food to entice fish; taunt" , "N in radio comms" , "Used to lure fish or other animals into danger" , "Angler's lure for fish" , "Deliberately annoy or taunt" .)