Origin: Latin prefix trans-
Transformer has 3 different meanings across 1 category:
an electrical device by which alternating current of one voltage is changed to another voltage
"The transformer stepped down the high-voltage electricity from the power line so it could safely enter our home."
Something that transforms, changing its own or another thing's shape.
"The child spent hours carefully converting his transformer from a roaring truck into a standing soldier with snapping joints and moving arms."
A toy in the Transformers toyline which has mechanical parts that allow it to be altered in appearance from its original form as a humanoid robot action figure to another form, usually a vehicle, depending on the toy.
In plain English: A transformer is an electrical device that changes voltage levels to make electricity safer for use in homes and businesses.
"The city sent a repair crew to fix the transformer that had blown during the storm."
Usage: In electrical contexts, this term refers specifically to the device that changes voltage levels, whereas in general usage it denotes any agent of change. Avoid using "transformer" as a verb; use "to transform" instead.
The word transformer is formed by adding the suffix -er to the verb transform. It was first used to describe a device that changes electrical voltage, following the pattern of other agent nouns ending in -er.