"Milden" is a word that is not commonly used in everyday language, and as such, it may be challenging to find suitable synonyms. However, some synonyms for "milden" include "soften," "temper," "mitigate," "alleviate," "pacify," and "calm." These words all suggest the idea of reducing the intensity of something, making it less extreme or severe. For example, you can use "soften" to describe making someone's harsh words less hurtful or "mitigate" to refer to reducing the effects of a natural disaster. In short, synonyms for "milden" can help us describe situations where we wish to temper or reduce the impact of something.