Well, it depends on whether this shipping involves drugs, or some kind of sailboat. If the former, try definiton number 5 at this site: http://dictionary.reference.com/browse/mule If the latter, try definition number 8.
mule
Stubb is the mountain canary that thinks he is a mule.
These wild kids, in this day and age, are more stubborn than a mule.My grandfather once owned a mule on his farm.
There is no abstract noun for the word mule; a mule is a physical thing and any synonyms for mule would also be physical nouns, for example animal or mammal. A concrete noun can be used in an abstract context, for example: We hear the sound of the ghost mule's hoof beats at midnight.
slow
mule = Maultier mule = Muli
A saddle mule is a mule used for transportation or riding, were as a pack mule is a mule used solely for transporting luggage rather then people.
Mule Skinner
mule = Maultier mule = Muli
A donkey can have offspring that is a mule, a mule cannot have offspring that is a donkey.
tête de mule (addressing the stubborn mule), têtu/têtue comme une mule (describing someone as stubborn as a mule) are standard French expressions.
mule
The name for a male mule is a Jack.
A mule is a cross between a horse and a donkey. A mule is sterile.
The French word "mule" typically refers to a type of shoe that has a closed toe and an open back. It can also refer to a hybrid animal that comes from crossing a horse and a donkey.
Mules are sterile, a mule is the offspring of a donkey and horse, therefore sterile. A male mule can mate with a female mule, but will never get her pregnant.
The mule hauled my cart up the hill. The lady bought a mule for her "car". Do you know what a mule is? A mule is a weird but kind animal. (I think) Hope this helps! Peace out~Tj8rocks