Other forms: sheepdogs
A sheepdog is the dog trained to gather and drive sheep. A working sheepdog, sheepdog trials, whistle to the sheepdog.
The border collie works by staring at the sheep rather than by barking, using the same instinct a wolf uses to single an animal out, stopped just short of the kill. A trained dog answers to whistles at a distance where a voice would not carry.
1nounsheepdogThe dog trained to gather and drive sheep.
“The farmer whistled, and the sheepdog raced round the flock and drove it into the pen.”
sheepdog is a dog.
Sheep plus dog, a plain compound recorded from the eighteenth century.
From sheep + dog.
Etymology from Wiktionary, CC BY-SA