bobtail /ˈbɑbteɪl/noun 8verb 2forms 3 noun8 •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. •The tractor unit of a semi-truck without a trailer. •A tractor-trailer that is relatively short in length. •A bobtail squid. •[before a noun] An open-ended straight or four flush. •A bobtail skink. verb2 •To drive a tractor without its trailer.He deposits his trailer at a Marten facility in nearby Stockton, and then drives without the trailer - that's called "bobtailing". — 2002 •To drive a truck or other vehicle without its trailer.W.C. Bergmann was supplementing his meager lamplighter's income by "bobtailing"… picking up laundry and cleaning in his horse drawn truck... — 2003 formsbobtailed · bobtailing · bobtails