Contrary to what you may believe, this euphemistic labeling is not the work of marketing geniuses. Rather, it is the work of the bodies that determine labeling (in the US, it would be the Food and Drug Administration). There are very specific rules about what labeling a beverage must contain, and how that labeling must look.
Per the FDA's website:
J5. Should my product be labeled as a “drink” or a “beverage?”
Answer: Beverages that are 100% juice may be called “juice.” However, beverages that are diluted to less than 100% juice must have the word “juice” qualified with a term such as “beverage,” “drink,” or “cocktail.” Alternatively, the product may be labeled with a name using the form “diluted __ juice,” (e.g. “diluted apple juice”). 21 CFR 102.33(a)
J7. What statement of identity is used on a mixed fruit or vegetable juice beverage?
Answer: When stated, names of juices must be in descending order of predominance by volume, unless the label indicates that the named juice is used as a flavor. Examples:
“Apple, Pear and Raspberry Juice Drink”
“Raspberry-Flavored Apple and Pear Juice Drink”
If the label represents one or more but not all the juices (except in the ingredient list), then the name must indicate that more juices are present. Examples:
“Apple Juice Blend”
“Apple Juice in a Blend of Two Other Fruit Juices”
When one or more, but not all, juices are named and the named juice is not the predominant juice, the name of the beverage must either state that the beverage is flavored with the named juice or declare the amount of the named juice in a 5% range. Examples (for a “raspcranberry” beverage that is primarily white grape juice with raspberry and cranberry juices added):
“Raspcranberry Raspberry and Cranberry flavored Juice Drink”
“Raspcranberry Cranberry and Raspberry Juice Beverage”
“10-15% Cranberry Juice and 3-8% Raspberry Juice”
21 CFR 102.33(b), 21 CFR 102.33(c), 21 CFR 102.33(d)
J8. What type sizes must be used in naming juices?
Answer: The term “from concentrate” or “reconstituted” must be no smaller than one-half the height of the letters in the name of the juice. The 5% range information generally should be not less than one-half the height of the largest type appearing in the common or usual name (may not be less than 1/16th inch in height on packages with 5 sq. in. or less area on the PDP, and not less than 1/8 inch in height on packages with a PDP greater than 5 sq. in.). 21 CFR 102.5(b)(2), 21 CFR 102.33(d), 21 CFR 102.33(g)
As I see you are in the UK, here is a link to some of their relevant labeling policies.
The moral of the story: Look before you buy.