Lucre is another word for money, or profit. It's most often used to describe money gotten illegally or immorally.
Well-heeled bankers and lawyers make profits; drug dealers and bank robbers get filthy, rotten lucre. You might think of lucre as the term that gets at the dark side of capitalism. Some people will do anything in the pursuit of lucre. Political groups that call Hollywood immoral still accept the lucre that it offers. We all love money, except when it causes us to do terrible things to ourselves and others. Then it's lucre.