beast of burden 
noun
An animal, such as a mule or donkey, that is used for carrying loads.Ancient Egyptian art depicts this animal as their domesticated beast of burden....
- The llama was domesticated as a beast of burden, while the alpaca was kept for its wool, and the guinea-pig for meat.
- For many years, this intelligent and docile animal has been used by man as a beast of burden, circus performer, and even as a weapon of war.
- inverted pendulum
- inverted snob
- inverted snobbery
- inverter
- invertibility
- invertible
- invert sugar
- invest
- investable
- investible
- investigable
- investigate
- investigation
- investigational
- investigative
- investigator
- investigatory
- investiture
- investment
- investment adviser
- investment analyst
- investment bank
- investment banker
- investment banking
- investment bond