おとな大人otonaしいshii
1.
Characterized by a calm and gentle demeanor, often displaying a willingness to listen and engage without raising one's voice or causing disruption.
2.
Exhibiting a serene and composed nature, making one approachable and easy to manage, often used to describe pets or individuals who are non-confrontational.
3.
Demonstrating a simple and understated aesthetic, lacking ostentation, which is considered appealing and tasteful in design or appearance.
Example:
牛は大きくて、おとなしく見えました。