Type of bond created by this ancient order (5)
I believe the answer is:
ionic
I believe this clue is a double definition.
'type of bond' is the first definition.
(I've seen this in another clue)
'this ancient order' is the second definition.
(I've seen this before)
'created by' is the link.
(Other definitions for ionic that I've seen before include "Greek tongue" , "in ancient Greece?" , "Greek order" , "Classical verse" , "Description of bond" .)