[Houghton M.]

Nosus decipio is nonsense, gibberish. Whoever wrote this is illiterate in Latin.

[Mr Rogers]

“In all the Internet citations of the phrase, the word nosus is never explained, but (as in this Wikipedia citation) the verb decipio (”I cheat”) is frequently referred to. Nosus does not look like Latin at all. It occurs to me that it might be a misspelling for notus (pparticiple of nosco, “I know”) so our phrase could mean something like “I am a known cheat.”

http://www.translatum.gr/forum/index.php?PHPSESSID=30239a6cf4e9bad8da69828001fca14a&topic=121281.0#ixzz1F5NBeW9a

Looks like a phrase made up by someone for a film, and now assumed to be accurate.

[DrC]

“Nosus decipio is nonsense, gibberish.”

I assume nos decipio would be correct?

[cycjec]

Thanks. It’s a screenwriters effort, judging from the
OP.