Be indebted to (3)
(Other definitions for ore that I've seen before include "Mineral deposit" , "Naturally occurring mineral" , "not worth a lot to Danes" , "Raw material" , "Unwrought iron" .)
'be indebted to' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for owe that I've seen before include "overdrawn" , "Be obliged to pay" , "Be in the red" , "Be indebted" , "Be beholden" .)