| Noun | 1. | seltzer - naturally effervescent mineral watermineral water - water naturally or artificially impregnated with mineral salts or gasses; often effervescent; often used therapeutically |
| 2. | seltzer - effervescent beverage artificially charged with carbon dioxidesoda pop, soda water, tonic, pop, soda - a sweet drink containing carbonated water and flavoring; "in New England they call sodas tonics" drinking water - water suitable for drinking |