reformer

noun

1. One who reforms, or who works for reform.

   “Among the frontrunners before the conclave began were Pietro Parolin, the Vatican’s secretary of state; Luis Antonio Tagle, a reformer from the Philippines; Péter Erdő, a traditionalist from Hungary; Robert Sarah, a cardinal from Guinea who criticised Francis’s papacy; and the moderate US cardinal Robert Prevost.”

2. (historical)One who was involved in the Reformation.

   “[…] for I long to ſee a larke without a creaſt, and would travaile farre to diſcoover a reformer without a fault, […]”

3. A device which converts hydrocarbons into a hydrogen-rich mixture of gases.

   “The fuel reformer works somewhat like catalytic converters in cars. In the gasoline reformer, vaporized gasoline is mixed with steam and air before traveling through a cylinder packed with the new Argonne catalyst. The result is a hydrogen-rich gas that is further processed in subsequent chemical steps and is then fed to the fuel cell.”

4. A device used to convert petroleum refinery naphthas, typically having low octane ratings, into high-octane liquid products called reformates.

   “Deisohexanizer bottoms are routed to the continuous reformer, where the octane of the stream is upgraded chiefly by conversion of naphthenes and paraffins to high octane aromatic compounds.”

5. (alt-of, historical)Alternative letter-case form of reformer (“one involved in the Reformation”).
6. (Canada, historical)A member of the Reform movement in 19th-century Canada.
7. (Canadian)A member of the Reform Party of Canada, which existed from 1987 to 2000.
8. (UK)A member or supporter of Reform UK.