soda water

/S OW1 D AH0 W AO1 T ER0/
noun
  1. 1

    Carbonated water, water that has carbon dioxide dissolved in it and has been stored under pressure in a bottle. Usually mixed before drinking with another beverage.

    "Scotch and soda" is a mixture of Scotch whisky and soda water.

Source: https://en.wiktionary.org/wiki/soda%20water