Blended is a term most often associated with Whisky.
90% of whisky sales around the world are Blended Whisky. Often Blended Whiskies are cheaper than single malts, (in particular they tend to be the affordable end of Scotch Whisky), but that doesn’t mean that single malts are better drinks.
Many people confuse Single Malt with Blended because Single Malt is itself a blended product. The key difference is that Blended Whisky refers to blending the whisky from multiple different distilleries, while Single Malt are all taken from the same distillery (i.e. multiple barrels all from the same distillery mixed together to build enough volume). The term Blended is regulated by the industry.
Blended Malt Whisky is whisky made by combining malt whiskies from different distilleries.
Blended Grain Whisky – whisky made by combining grain whiskies from different distilleries.
Blended Whisky – whisky made by combining malt whisky and grain whisky
Blended Gin – In this context, the term refers to the process used to create the end spirit. Some producers individually distil each botanical and then blend the resulting distillates together to form the final gin. While it’s not an uncommon process, Blended Gin isn’t something you see often as a naming convention nor is it regulated. The term is more a guide to help drinkers understand how it is made, rather than something that is regulated (like London Dry Gin).