We don't have synonyms for farcing yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are facing, farming and farting.
(n) :
Alternative form of farsing (“the insertion of vernacular paraphrases into a Latin liturgy”). [The insertion of vernacular paraphrases into a Latin liturgy.]
(n) :
Alternative form of farsing (“the insertion of vernacular paraphrases into a Latin liturgy”). [The insertion of vernacular paraphrases into a Latin liturgy.]