a Woolly Bugger is a Woolly Worm with a marabou tail. Simple as that. People are forever changing flies and calling them something they are not.

A Griffith's Gnat is a small Woolly Worm with dry fly hackle so it floats. Murray's Hellgrammite is a Woolly Bugger with an ostrich herl tail. Ten million variations on these flies all called something else.

Bugger: soft marabou (or marabou-like) tail about as long as the hook shank. Worm: short tag-tail of yarn or other fibers, not extending past the hook bend, or no tail at all.

Simple and widely-accepted.