turnspit
/ˈtɜːnspɪt/noun
1- historical a servant whose job was to turn a spit on which meat was roasting〈史〉（负责转动烤肉叉的）转叉雇工。
1.1
- a dog kept to perform this task by running on a treadmill connected to the spit（经训练能用踏轮转动烤肉叉的）转叉狗。