Spot with attendant exudation (7)
I believe the answer is:
seepage
'exudation' is the definition.
(I've seen this in another clue)
'spot with attendant' is the wordplay.
'spot' becomes 'see' (both can mean to notice or observe).
'with' is a charade indicator (letters next to each other).
'attendant' becomes 'page' (page is a kind of attendant).
'see'+'page'='SEEPAGE'
(Other definitions for seepage that I've seen before include "narrow escape?" , "running out slowly" , "Leaking liquid" , "Discharge" , "Slow leakage" .)