What is a metaphorical extension in semantic change?

• A. Mouse, originally an animal, used for a computer device
• B. A word gains a new sense via metaphor
• C. A word loses its meaning and becomes a filler
• D. A word is borrowed from another language entirely

Answer: (A)

Metaphorical extension happens when a word’s meaning broadens by applying the traits or associations of something familiar to another thing, using metaphor to bridge the gap. The example of naming a computer input device a “mouse” fits this perfectly: the device is called after the animal because of its small, rounded shape and the way it moves, which resembles a mouse scurrying around. That mapping from animal to object creates a new sense for the word in a concrete, widely recognizable way, illustrating how a metaphor extends meaning into a new domain.

The other ideas describe related processes but don’t show the extension in action as clearly. One describes the general idea of gaining a sense through metaphor, which is close but vaguer and less demonstrative than a real-world instance. The remaining options point to different phenomena (loss of meaning, or borrowing from another language), which are not about extending meaning through metaphor.