Why is the ninth month called September?
1560s, from Late Latin falsificationem (nominative falsificatio), noun of action from past participle stem of falsificare (see falsify).
mid-15c., "to prove false," from Middle French falsifier (15c.), from Late Latin falsificare (see falsify). Meaning "to make false" is from c.1500. Earlier verb was simply falsen (c.1200). Related: Falsified; falsifying.
falsification fal·si·fi·ca·tion (fôl'sə-fĭ-kā'shən)
The deliberate act of misrepresentation so as to deceive.