What is the meaning of Bobtail?

A short, or deliberately shortened tail.

An animal that has a bobtail, such as certain canines or nags.

A tractor which performs without its trailer.

A tractor-trailer that is relatively short in length.

1. The tractor unit of a semi-truck without a trailer.

The tractor unit of a semi-truck without a trailer.

An open-ended straight or four flush.

A bobtail squid.

A bobtail skink.

To drive a tractor without its trailer.

To drive a truck or other vehicle without its trailer.

Old English Sheepdog

Source: wiktionary.org