1700s

Completely and helplessly, especially completely in love; also, literally, turning a somersault or tumbling upside down.

A costly possession that is more of a burden than a benefit — something expensive to keep, hard to get rid of, and of little practical use.

Feeling ill, unwell, or slightly out of sorts.

Something that seems bad or unfortunate at first but turns out to have a good or beneficial result.

To die, used as a light, faintly comic euphemism that avoids the bluntness of saying someone has simply died.

A bigwig is an important, powerful or high-ranking person, especially one whose self-importance the speaker finds faintly ridiculous.

To mind your Ps and Qs is to be careful about your behaviour, manners, and words, especially to avoid giving offence.

Son of a gun is a mild exclamation of surprise or annoyance, or a jocular, half-affectionate term for a man or rogue.

Raining very heavily; a vivid, hyperbolic expression for a downpour of unusually intense and torrential rain.

To let the cat out of the bag is to disclose a secret, often carelessly or prematurely, revealing something that was meant to be hidden.