reducer

漢語翻譯

n. 漸縮管, 縮減者, 還原劑
【化】 變徑段; 變徑管; 異徑管; 大小頭; 還原劑; 減速器; 減振器; 節流器

英文解釋：

名詞 reducer:

1. a substance capable of bringing about the reduction of another substance as it itself is oxidized; used in photography to lessen the density of a negative or print by oxidizing some of the slackened silver
   同義詞：reducing agent, reductant
2. pipefitting that joins two pipes of different diameter