Trend seen regularly in fraud (3)
I believe the answer is:
fad
'trend' is the definition.
(a fad is a brief craze or fashion)
'regularly in fraud' is the wordplay.
'regularly in' indicates alternate letters.
The alternate letters of 'fraud' are 'FAD'.
'seen' is the link.
(Other definitions for fad that I've seen before include "A craze or current vogue" , "Craze; idiosyncrasy" , "Passionate interest" , "A passing fancy or fashion" , "transient success" .)