Either terribly neat or highly decorated (6)
I believe the answer is:
ornate
'highly decorated' is the definition.
(I've seen this in another clue)
'either terribly neat' is the wordplay.
'either' becomes 'or' (I've seen this in another clue).
'terribly' is an anagram indicator.
'neat' with letters rearranged gives 'nate'.
'or'+'nate'='ORNATE'
'or' is the link.
(Other definitions for ornate that I've seen before include "Richly adorned and elaborate" , "Rich in decorative detail" , "Excessively decorated" , "Fancy" , "Florid" .)