Douglas Harper's Etymology Dictionary
Wiktionary
alt. A person who is visually similar to another; a double. n. A person who is visually similar to another; a double.
WordNet
Wikipedia
A look-alike, or double, is a person who closely resembles another person. In popular Western culture, a look-alike is a person who bears a close physical resemblance to a celebrity, politician or member of royalty. Many look-alikes earn a living by making guest appearances at public events or performing on television or film, playing the person they resemble. A large variety of celebrity look-alike images can be found throughout the web, including images placed by professional agencies that offer their services.
Look-alikes have also figured prominently at least since the 19th century in literature, and in the 20th and 21st centuries also in films and TV series.
Usage examples of "look-alike".
Here is a miniboom of look-alike public housing, the pickup-crowded parking lots of Fairchild Semiconductor, the bustle of the oil and gas industry, the beginnings of a tourist industry.
Only a few faces come back: the old woman in the cafe, the Frank Zappa look-alike and the manager in the Regency pub. None of those fit his image of the private detective, yet somebody was watching.
There might be dead people reanimated in that line, Kelvin thought with a shudder, or even look-alikes from other frames.
Minutes later the Stucker look-alike, still buttoning his trousers, comes out of the very copse where later we find what’s left of the real Stucker.
Several dogs investigated the two Iryalans, and while they definitely seemed to be genus Canis rather than some canoid look-alike, they were neither hostile nor noisy.
This one was costumed as an Elvis look-alike, with a ducktail haircut and a swagger, about twenty-five.
The drone is a long-legged crane fly look-alike, bouncing very slowly from toe tip to toe tip in the microgravity.
I want a look-alike for Borden at the clambake, and two luckless fishermen in a little rowboat right offshore, dead ringers for the saints Stanley Laurel and Oliver Hardy.
He was bald, with just a fringe of hair, and obviously well-fed, but otherwise he was another member of the look-alike set that included President Millard Grotsky, Sam, Sid, and all the other bodyguards.
The high cabs of the vehicles made for excellent visibility, and the meanderings of the look-alike vehicles appeared far less sinister than would those of unmarked sedans.
Prosecution replied that the defendant was deliberately obstructing justice by appearing with look-alike escorts.
He is a little thing, a sheltie, not a Lassie look-alike but just another brown hairy.
And if we fail--and we have to face the fact that we might fail--then at least we will return with considerable data on a dozen different stars, a white dwarf, a blue-white hot star, a Solar look-alike, a close binary, and so on.