Compound Gin is a term that’s used for Gins that have been made without distillation.
Compound Gins are commonly made by flavouring a Neutral Spirit base with essences or other natural flavourings. It is also possible to make them by steeping actual botanicals in a Neutral Spirit base (also known as a Bathtub Gin) and while that’s the most known and talked about (namely as their producers are proud to show how they are made and that there’s no hiding the natural tint that occurs to the liquid), there are far fewer of these gins than there are those who use essences and flavourings alone.
Compound gins are less common in the UK and the US as they are in Spain or Belgium, where there are dozens and dozens of examples on shelf – not all of which are labelled as such.