What does bobtail mean?
A bobtail is a tail that has been cut short or docked, or an animal that bears such a tail. The term applies most familiarly to dogs — several breeds, including the Old English Sheepdog, are traditionally associated with short or absent tails — as well as to sheep and horses whose tails are trimmed for practical or customary reasons. In some animals the short tail occurs naturally rather than through docking, so 'bobtail' can describe either a surgical result or a genetic trait. The word also carries a distinctly American colloquial sense in trucking, where a 'bobtail' is a semi-tractor running without its trailer. Historically, docking served working purposes: shepherds and farmers believed it prevented injury and disease among flocks, and in eighteenth-century Britain docked working dogs were exempt from a pet tax. Today the word survives both in breeding terminology and in everyday speech about animals, carrying connotations of rustic, working-life tradition.
A tail cut or docked short; an animal with such a tail.
"The farm collie had a bobtail from generations of working-dock tradition."
To dock an animal's tail short (rare).
"Farmers used to bobtail their sheep each spring."
This verbal sense is uncommon; 'dock' is the standard verb.
(US, informal) A semi-truck tractor operating without a trailer attached.
"He drove bobtail back to the depot after dropping the load."
Used mainly within the American trucking industry.
Standard plural, used when referring to multiple animals or trucks with bobtails.
"The field was full of bobtails grazing contentedly."
The Old English Sheepdog breed was once required by British law to have its tail docked — which is why owners paid lower 'dog tax' on bobtailed working dogs.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of bobtail
Bobtail derives from the Middle English word 'bob', meaning a short, stubby bunch or lump — the same root behind 'bob' of hair and 'bobbing' movement. It combines 'bob' with 'tail' to form a compound describing a shortened tail, first attested in the early seventeenth century. The element 'bob' also gives us related words such as 'bobble' and 'bobbin', all sharing the notion of something short or round.
How bobtail is actually used
Most often used in reference to certain dog breeds (such as the Old English Sheepdog and Pembroke Welsh Corgi) and docked livestock. The trucking sense is distinctly American and colloquial within the industry.
Easily confused with bobtail
Curtail is a verb meaning to reduce or limit something, whereas bobtail refers to a short-cut tail, an animal with one, or a trailer-less truck.