It's an old term, not one often used in the Latin church for Holy Wednesday but it makes a good point. The gospel on this day describes Judas Iscariot's agreement to lead his enemies to Jesus under the cover of darkness at a place and a time when no crowds would be present.
The eleven disciples with Jesus at the Last Supper didn't seem to know Judas' plan and to misunderstand or not hear Jesus' dialogue with Judas. Otherwise they would have restrained Judas from fleeing into the night to put his plan in motion.
Scholars speculate about Judas' motives for betraying Jesus, but the Scriptures describe an important reason: money. Whether or not Judas was disappointed at Jesus' interpretation of his suffering Messianic role and wanted a more powerful opposition to the Roman occupation cannot be known. Thirty pieces of silver was not a life-changing sum of money and hence the search for non-financial reasons for Judas' treachery.
Treachery needs secrecy and the cover of darkness. Otherwise good people can oppose it and win. Betrayal, by definition, must come from a friend.
Money, power, greed, mammon are all names for the same thing: temptations for potentially good people to do evil for a temporal reward.
Treachery is afoot. This Holy Week let us pray to be of one mind and heart in Jesus Christ. Let us admit our sinfulness and the ever-present temptation to trade eternity for temporal goods and ask God's strength to resist the power of Satan in our lives.
And let us pray for God's protection for Christians all around the world.