Fortunetellers (7)
'fortunetellers' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for seers that I've seen before include "Prophets" , "They have visions of the future" , "Visionaries" , "They divine the future" , "wise men" .)
(Other definitions for oracles that I've seen before include "Places where ancient Greek consulted their gods" , "Prophets, seers" , "They were consulted by ancient Greeks" , "Wise utterances" , "Authoritative sources" .)