loud的反义词有low、quiet、soft。

1、low意思：adj. 低的；少的；低落的；低声的；卑劣的；低等的例句：I asked them to turn the volume down low.我叫他们把音量调低一点。

2、quiet 意思：adj. 安静的；宁静的；平静的例句：When you are in a library, you must be quiet.当你在图书馆时,你必须保持安静。

3、soft意思：adj. 柔软的；柔和的；温和的；不强烈的；轻的例句：His voice was soft and I lost some of his words.他的声音很轻，有些话我没有听到。