FDA Says, Natural flavor:
CFR - Code of Federal Regulations Title 21: Natural flavor
(3) The term natural flavor or natural flavoring means the essential oil, oleoresin, essence or extractive, protein hydrolysate, distillate, or any product of roasting, heating or enzymolysis, which contains the flavoring constituents derived from a spice, fruit or fruit juice, vegetable or vegetable juice, edible yeast, herb, bark, bud, root, leaf or similar plant material, meat, seafood, poultry, eggs, dairy products, or fermentation products thereof, whose significant function in food is flavoring rather than nutritional. Natural flavors include the natural essence or extractives obtained from plants listed in §§ 182.10, 182.20, 182.40, and 182.50 and part 184 of this chapter, and the substances listed in § 172.510 of this chapter.
A little more on "natural flavors":
Natural flavors are essentially anything you extract from a plant or
animal source; in contrast to artificial flavors, which are chemicals
originating in a lab.16 But despite being derived from a single
natural source, the resulting natural flavor complex buyers eventually
consume is far different from the derivative.17 In the end, the
flavors “are mixtures of chemicals obtained by applying physical
separation methods” to natural sources, and the result of a lengthy,
complex process.18 Once ready for consumption, these natural flavor
mixtures can contain as many as 250 chemically identified
constituents, some of which are artificial and synthetic.19Natural
flavors and the amalgamation of chemical constituents that comprise
the ingredient can often be found on the back of products labeled as
“Natural.” While there is much commentary online20 questioning the
naturalness of these “natural flavors,”