Old priest the Spanish idolised originally (3)
I believe the answer is:
Here is my best explanation:
'old priest' is the definition.
'the spanish idolised originally' is the subsidiary indication.
'the spanish' becomes 'el'.
'originally' suggests taking the first letters.
The initial letter of 'idolised' is 'i'.
(Other definitions for eli that I've seen before include "Highest priest at Shiloh", "Biblical teacher of Samuel", "- Wallach, US actor", "Old Testament high priest", "Old Testament priest, the prophet Samuel's teacher", "Teacher of Old Testament", "High priest in the Book of Samuel", "OT high priest", "Distort then untruth to get a Biblical character" and "Man's name".)