1. a person with golden hair —used as a nickname
"How well Queenie looks in that soft light!" "Dear little Goldilocks looks well everywhere." And with a backward glance full of pride and fondness, Mrs Jo went on.
— Louisa May Alcott

2.

3. a European composite herb (Galatella linosyris) with heads of yellow flowers resembling those of goldenrod

4. any of several shrubby southern African composite plants (genus Chrysocoma) that have bright yellow flower heads

5. a European buttercup (Ranunculus auricomus)

6. having or producing an optimal balance usually between two extremes
While Davis is willing to buy into companies that are cutting dividends, his real focus is Goldilocks stocks, whose yields are neither too high nor too low.
— David K. Randall At the right time he lay on his surfboard looking over his shoulder searching for what he calls a "Goldilocks wave," one that is just right.
— Paul Doherty et al. In order to succeed, humanitarian efforts require a "Goldilocks" solution—just the right mix of force and charity, sympathy and structure, blind will and determined follow-up.
— Wilfred M. McClay specifically, astronomy lying in or being an area of planetary orbit in which temperatures are neither too hot nor too cold to support life
The planet is smack in the middle of what astronomers call the Goldilocks zone, that hard-to-find place that's not too hot, not too cold, where water, which is essential for life, doesn't freeze or boil.
— The Recorder (Greenfield, Massachusetts) … with nearly 500 exoplanets under their belts, astronomers still haven't found an Earth-size planet in a star's habitable zone—also known as the Goldilocks region, where things are not too hot, not too cold, but just right for life.
— Michael D. Lemonick To qualify as "Earthlike," a planet must not only fall within a reasonable approximation of Earth's composition, mass, gravity, and spin. It must also be located in what astronomers have dubbed the "Goldilocks orbit."
— William Harwood Not all stars of course, are likely to have planets, especially what researchers call "Goldilocks" planets—not too hot and not too cold for life. And not all life is likely to be intelligent.
— Mike Toner