### Question
What does unit mean?


### Answer
**Unit** has the following meaning in *42 U.S.C. § 7651a*:

> a fossil fuel-fired combustion device

#### Citation:
  - *42 U.S.C. § 7651a*
  - Heading: **CHAPTER 85-AIR POLLUTION PREVENTION AND CONTROL > SUBCHAPTER IV&ndash;A-ACID DEPOSITION CONTROL**

