It seems that some people refer to clones as simply specific cultivars and others mean it to suggest they’re plants arrived at through means other than selection massale.
whixh is it?
Jamie Goode has a good write-up in his The Science of Wine, "Some of these differ through spontaneous bud mutations, which then result in genetically altered shoots...and can be propagated by cuttings taken from such an affected shoot, resulting in a new clone of the variety." In a quote from José Vouillamoz later in the text, he states that the definition of 'clone' is not entirely clear, but mostly as an aggregate of mutations that are noticeable enough for humans to select for them (p. 19). There is also an oldy-but-goodie Guildsomm article here.