n.
1.a metaphor that has occurred so often that it has become a new meaning of the expression (e.g., `he is a snake' may once have been a metaphor but after years of use it has died and become a new sense of the word `snake')
Idiom of the Day
in the charge of
under the care or supervision of
The girl has been in the charge of her grandmother since the girl's mother and father died.