perfidy perfidiousness • perfilograph · · · Info · Definitions · Synonyms · Characters · · perfidy · · Text Latin · · Script 7 · · Length 3 · · Syllables Definitions · · · (noun) betrayal of a trust. Synonyms: perfidiousness, treachery. · · Noun Definition 1 (noun) an act of deliberate betrayal. Synonyms: treachery, betrayal, treason. · · Noun Definition 2 Synonyms · · · perfidiousness · · Synonym 1 treachery · · Synonym 2 betrayal · · Synonym 3 treason · · Synonym 4 Characters · · d latin small letter d U+0064 e latin small letter e U+0065 f latin small letter f U+0066 i latin small letter i U+0069 p latin small letter p U+0070 r latin small letter r U+0072 y latin small letter y U+0079