tax break

A special tax benefit given to promote specific economic or social objectives. For example, the U.S. government, having decided that individual home ownership is a boon to the economy, allows interest on a home mortgage to be subtracted, in whole or in part, from one's taxable income. The resulting lower taxation for homeowners constitutes a tax break.

The noun has one meaning:

Meaning #1: a tax deduction that is granted in order to encourage a particular type of commercial activity
  Synonym: tax benefit