Information a bit topsy-turvy (4)
I believe the answer is:
data
'information' is the definition.
(thesaurus)
'a bit topsy-turvy' is the wordplay.
'bit' becomes 'tad' (I've seen this before).
'topsy turvy' is a reversal indicator.
'a'+'tad'='atad'
'atad' written backwards gives 'DATA'.
(Other definitions for data that I've seen before include "Numerical facts" , "tables, perhaps" , "Collection of facts, information" , "Organised information" , "Facts given" .)