Nectar is a marketing term that came about in the late 1980s for a non-pure, diluted fruit juice to distinguish it from other non-pure fruit drinks.
A “Nectar” will contain added water, added sugar or honey to sweeten it, and often contains fruit pulp to make it thicker than juice.
There are no real standards yet (as of 2004) as to how much juice must be present, but generally producers are making it with anywhere from 25 to 60% juice.