Definition & Meaning of "good gravy"in English

What is the origin of the exclamation "good gravy" and how is it used?

Good gravy is an exclamation used to express surprise, amazement, or mild exasperation. It appeared in American English in the early 20th century as a playful euphemism for "good God," allowing speakers to react strongly without swearing. People used it in everyday conversation, comic strips, and radio to convey astonishment or irritation in a lighthearted way. Today it is inoffensive, whimsical, and slightly old-fashioned, often adding a humorous or gentle emphasis to expressions of surprise or mild frustration.