Shaking in my boots is an idiomatic expression, building around the idea of someone being so terrified that he or she is trembling in fear.
The term “shaking like a leaf” carries a similar meaning to the expression mentioned above, as a shaking movement and tremor is often associated with anxiety or despair.
The origin of this phrase is unclear. Some language experts claim that it developed somewhere in the 19th century, but there is no clear evidence supporting these claims.
British journalist and politician William Cobbett mentioned a similar phrase in one of his publications, in the early-1800s: “This is quite enough to make Corruption and all her tribe shake in their shoes”.
Reacting to fear by shaking is a common experience that everyone encounters, regardless of culture or nationality.
For this reason, shaking in my boots became a widespread expression around the world, and is found as an idiom in most languages.
Miss Portia, an American R&B artist named her song after this particular idiom, which was released in 2018.
The idiom is also featured in the 1999 movie Austin Powers: The Spy Who Shagged Me, uttered by the character of Dr. Evil (portrayed by Mike Myers).