a person who restrains a chemical, such as potassium bromide, added to a photographic developer in order to reduce the amount of fog on a film and to retard the development
WordReference Random House Unabridged Dictionary of American English © 2025
re•strain•er
(ri strā′nər),USA pronunciation n.
- a person or thing that restrains.
- Photographya chemical added to a developer to retard its action.
- restrain + -er1 1560–70
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