When we think of cronyism, we are really thinking about rent-seeking. So, let us define rent-seeking.
In economics, rent-seeking is an attempt to obtain economic rent by manipulating the social or political environment in which economic activities occur, rather than by creating new wealth. For example, spending money on political lobbying in order to be given a share of wealth that has already been created. http://en.wikipedia.org/wiki/Rent-seeking