Thats the government line. But in reality what are they? Here is a good working definition of income tax
Question. Are social security payments imposed by the government? Are they based on financial income? Are you required to fill out a return indicating your payment amount? Are these funds used to fund government activities and serve the public?
Again a rose by any other name is still a rose.
Dictionary definitions are not relevant.
The letter of law is the controlling authority in this area.