Dead metaphor (frozen metaphor)
Dead metaphor (frozen metaphor): A word or phrase once used as a metaphor (a direct comparison between two distinct things without like or as) that has become so familiar it is no longer perceived as one. Because the vehicle of a dead metaphor is no longer recognized as an image used to illustrate the tenor, or subject, the word or phrase is treated literally rather than figuratively. The term dormant metaphor is sometimes used to refer to a word or phrase that is in the process of dying as a metaphor; dormant metaphors are typically used literally, without regard to their figurative value, but can still be readily recognized as metaphors.
EXAMPLES: Keel over, toe the line, know the ropes, the foot of the bed. In “Renovations” (1977), a poem about the everyday business of taking a shower, Robert B. Shaw used a dead metaphor (“fiddling”) to strike an appropriately casual tone: “A twist, a little fiddling / With temperature, then in.” When we use the term fiddled (“I fiddled with the remote control”), no one thinks of playing the violin!