Thayer's Greek Lexicon

 1. to accuse wrongfully, to calumniate, to attack by malicious devices
2. to exact money wrongfully
  1) to extort from, defraud

At Athens those were "sukophantia" whose business it was to inform
against any one whom they might detect exporting figs out of Attica;
and as sometimes they seemed to extort money from those loath to be
exposed, the name "sukophantes" from the time of Aristophanes down
was a general term of opprobrium to designate, a malignant and base
accuser from love of gain.