Oddly, tried unknown orderly (4)
I believe the answer is:
tidy
'orderly' is the definition.
('tidy' is associated in meaning with 'orderly')
'oddly tried unknown' is the wordplay.
'oddly' indicates alternate letters.
'unknown' becomes 'y' (algebra).
The alternating letters of 'tried' are 'tid'.
'tid'+'y'='TIDY'
(Other definitions for tidy that I've seen before include "Spick-and-span" , "Businesslike" , "Substantial - orderly" , "Receptacle for odds and ends" , "Well-groomed" .)