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.
- protobird
- protobranch
- protocanonical
- protocatechuic
- protocell
- protoceratops
- protocercal
- protocerebrum
- proto-chemist
- proto-chemistry
- protochlorophyll
- protochordate
- protocloud
- protocluster
- protocneme
- protococcal
- defectiveness
- defector
- defeminise
- defeminize
- defence
- Defence Force
- defence in depth
- defenceless
- defencelessly