With urge to fascinate (5)
I believe the answer is:
witch
'fascinate' is the definition.
(thesaurus)
'with urge' is the wordplay.
'with' becomes 'w' (abbreviation).
'urge' becomes 'itch' (I've seen this in other clues).
'w'+'itch'='WITCH'
'to' is the link.
(Other definitions for witch that I've seen before include "charming female" , "Female practising black magic" , "'The Lion, the - - and the Wardrobe'" , "One supposed to have magical powers" , "Wise, wicked, woman" .)