A portmanteau of the words 'threat' and 'treachery': as in a threat that is treacherous.
The precursor to actually treachery.
1. Threatened by betrayal of fidelity, confidence, or trust.
2. An indication or caveat of perfidy.
3. Potential pain, injury, evil, or punishment that arrises from treason.
A rumour has reached the King's ear that his younger brother intends to topple him from his throne... 'This is threachery!'