1. （音乐）刺耳的，吵闹的
Brassy music is bold, harsh, and loud.

2. （女子）没有品位的，打扮花哨的，俗气的
If you describe a woman's appearance or her behaviour as brassy, you think that she does not have good taste, and that she dresses or behaves in a way that is too loud or vulgar.

3. 黄铜色的
Something that is brassy has a yellow metallic colour and sometimes looks cheap.