Strong's G2725 — κατήγορος (noun)
kategoros (kat-ay'-gor-os) n.
1. against one in the assembly, i.e. a complainant at law
2. (specially) Satan
[from G2596 and G58]
KJV: accuser 
Root(s): G2596, G58 
Hebrew root: ἀγορά
Occurrences: 5