sodium thiosulfate
nounUK /ˌsəʊdiəm ˌθaɪəʊˈsʌlfeɪt/
US /ˌsoʊdiəm ˌθaɪoʊˈsʌlfeɪt/
A white powder that dissolves in water and is used to stop chlorine from working.
The photographer mixed sodium thiosulfate to fix the picture so it would not fade.
OTHER MEANINGS
2. A chemical used in medicine to treat cyanide poisoning.
Doctors gave the patient sodium thiosulfate after the accident.
3. A compound used to neutralize chlorine in water, such as in fish tanks.
Add a little sodium thiosulfate to the tap water before putting in the fish.
4. A substance used in gold and silver extraction from ore.
The mine uses sodium thiosulfate to leach gold from crushed rock.