The term 'MIXER WITH GIN' refers to a type of drink that is made by combining gin with a mixer. The two most common mixers used are TONIC and TONIC water. TONIC is a carbonated beverage that is flavored with quinine, while TONIC water is a carbonated beverage that is flavored with quinine and sweetened with sugar or artificial sweeteners. Both TONIC and TONIC water can be used to make a variety of drinks, including the popular gin and TONIC.