Behaving in or having a mild or gentle manner(adjective)
WordNet. Princeton University. 2010.
Use "mild-mannered" in a sentence
"Described as "mild-mannered", this former Soviet double agent now lives in retirement in California with his wife Nadia and grown up daughter Olga, an occupational therapist."
"Described as mild-mannered and private, Lindner was also known as fiercely competitive and an eternal optimist who carried a stack of cards bearing sayings such as Only in America."
"Karim, described as "mild-mannered, well-educated and respectful", hid his hatred for Western ways from colleagues by joining a gym, playing football and never airing extreme views."