One who improves his or her performance, one who shows improvement (of individuals or groups).
Something that, or someone who, improves something.
A substance added to cause improvement (especially to a foodstuff).
A pad worn by women to make the dress hang properly.
One who reforms, or who works for reform.
One who was involved in the Reformation.
A device used to convert petroleum refinery naphthas, typically having low octane ratings, into high-octane liquid products called reformates.
A device which converts hydrocarbons into a hydrogen-rich mixture of gases.