Seductive invitation to approach (4-6)
I believe the answer is:
come-hither
'seductive' is the definition.
(I've seen this before)
'invitation to approach' is the wordplay.
'invitation' becomes 'come' (an invitation to come).
'to approach' becomes 'hither' (I can't explain this - if you can you should give a lot more credence to this answer).
'come'+'hither'='COME-HITHER'
Can you help me to learn more?
(Other definitions for come-hither that I've seen before include "Alluring" , "Seductive" , "Coquettish" .)