Multi-shot distilling is a term associated with the Gin industry and refers to the process with which the spirit is distilled.
A multi-shot method deliberately uses an overabundance of botanicals in order to produce spirit with a more concentrated flavour (which is also why it’s also sometimes referred to as a ‘concentrate’ method).
Once distilled the spirit is blended with Neutral Spirit, increasing the volume of liquid and adjusting the flavour profile of the concentrated spirit back to normal intensity. It is then diluted with water as usual, to reduce it to the alcoholic strength the distiller wants for bottling.