"She Swallowed Her Birth Certificate"

Andreas Kluth praises a collection of forgotten idioms:

Bhalla, a self-confessed monoglot, has collected idioms from the four corners of the world (eight corners, in Hindi) and returned, as he puts it, with “souvenir collections of linguistic gems". Why would the Germans have a single word that means the “disappointment one feels when something turns out not nearly as badly as one had expected”? Something about that seems quintessentially German, as Bhalla muses.

The official definition of an idiom, he explains, is “a group of words always used together as a phrase, where the meaning of the phrase isn’t clear from the meaning of the words in it.” For example, he kicked the bucket (or, in French, “he passed his weapon to the left” or “she swallowed her birth certificate”). Idioms are therefore “presolved cryptic word puzzles” or “fossilised metaphors” whose meanings were clear when they were coined but have since taken on a life of their own.