Definition & Meaning of "perish the thought"

What is the origin of the idiom "perish the thought" and when to use it?

The origin of the idiom "perish the thought" can be traced to the general use of the word "perish" in the sense of something coming to an end or ceasing to exist. The phrase likely evolved as an idiom to convey the idea that a particular thought or suggestion should cease to exist or be dismissed. It is often used in a reassuring or dismissive manner to counteract negative or undesirable ideas. While the exact historical origin of this specific idiom is not precisely documented, similar phrases and expressions invoking the idea of negating or dismissing thoughts or possibilities have been used in the English language for many years.