Even money, in truth (6)
I believe the answer is:
smooth
'even' is the definition.
(I know that even can be written as smooth)
'money in truth' is the wordplay.
'money' becomes 'm' (abbreviation used in economics).
'in' means one lot of letters goes inside another.
'truth' becomes 'sooth' (synonyms).
'm' going inside 'sooth' is 'SMOOTH'.
(Other definitions for smooth that I've seen before include "Regular - without problems" , "Free from roughness or irregularities" , "Glossy" , "Unruffled" , "Hairless" .)