A mineral bath is a type of SPA treatment that involves soaking in a pool of water that has been infused with minerals. It is believed to have therapeutic benefits, such as improving circulation and relieving stress. The term 'mineral bath' can also refer to a type of bathtub filled with mineral-rich water. The crossword solution for the term 'mineral bath' is SPA, which stands for 'sanus per aquam, ' meaning 'health through water.'