forfalskning in English:

counterfeit money

I was going to buy a bag from the man on the street, but then I realised it was probably counterfeit.

The counterfeit bills flooded the market over the weekend.

You are not allowed into the theatre because your ticket is a counterfeit one.

... simple research-- that the counterfeit customer was not our...

The word of God is the creation we behold and it is in this word, which no human invention can counterfeit or alter, that God speaketh universally to man.

Those people are true experts in the counterfeit of illegal things.