I work in an airline (cabin crew), and I know for a fact that there is no published list for such a thing.
Beside the famous (bomb, explosive, hijack, etc.) words, which is usually said by naive people trying to be funny, the current political situations and international or national threats related words/sentences would raise a flag. Cabin crew are trained to use common sense and they have the "veto right" to stop you from boarding a flight (after permission from the captain) if you have done/said something suspicious.
Anyway, since common sense is used to determine what words might be a sign of a threat it is totally different from one person to another, depending on the staff personality and background.
My advice, do not engage in any sensitive topics and do not try to be funny with the staff and or a fellow passenger using any sensitive words (Political, religious, etc.).
A story worth telling, a few weeks ago one passenger told a cabin crew member about the dream he had a day before his flight; he had a dream about crashing, the female flight attendant thought it is a sign of danger and request that the passenger gets offloaded! And he was offloaded.
Always remember, there is no time to waste in the aviation business, the decisions will be taken quickly even if it was wrong, they can not risk investigating the matter on the spot to avoid any delays which might be very expensive to the airline. So, for financial reasons in addition to the security reasons, you will be offloaded in case you used the wrong words, investigations and/or compensations shall come later.