It's Texas statute.
§ 46.01. DEFINITIONS. In this chapter:
(1) "Club" means an instrument that is specially
designed, made, or adapted for the purpose of inflicting serious
bodily injury or death by striking a person with the instrument, and
includes but is not limited to the following:
(A) blackjack;
(B) nightstick;
(C) mace;
(D) tomahawk.
(2) "Explosive weapon" means any explosive or
incendiary bomb, grenade, rocket, or mine, that is designed, made,
or adapted for the purpose of inflicting serious bodily injury,
death, or substantial property damage, or for the principal purpose
of causing such a loud report as to cause undue public alarm or
terror, and includes a device designed, made, or adapted for
delivery or shooting an explosive weapon.
(3) "Firearm" means any device designed, made, or
adapted to expel a projectile through a barrel by using the energy
generated by an explosion or burning substance or any device
readily convertible to that use. Firearm does not include a firearm
that may have, as an integral part, a folding knife blade or other
characteristics of weapons made illegal by this chapter and that
is:
(A) an antique or curio firearm manufactured
before 1899; or
(B) a replica of an antique or curio firearm
manufactured before 1899, but only if the replica does not use rim
fire or center fire ammunition.
(4) "Firearm silencer" means any device designed,
made, or adapted to muffle the report of a firearm.
(5) "Handgun" means any firearm that is designed,
made, or adapted to be fired with one hand.
(6) "Illegal knife" means a:
(A) knife with a blade over five and one-half
inches;
(B) hand instrument designed to cut or stab
another by being thrown;
(C) dagger, including but not limited to a dirk,
stilletto, and poniard;
(D) bowie knife;
(E) sword; or
(F) spear.
(7) "Knife" means any bladed hand instrument that is
capable of inflicting serious bodily injury or death by cutting or
stabbing a person with the instrument.
(8) "Knuckles" means any instrument that consists of
finger rings or guards made of a hard substance and that is
designed, made, or adapted for the purpose of inflicting serious
bodily injury or death by striking a person with a fist enclosed in
the knuckles.
(9) "Machine gun" means any firearm that is capable of
shooting more than two shots automatically, without manual
reloading, by a single function of the trigger.
(10) "Short-barrel firearm" means a rifle with a
barrel length of less than 16 inches or a shotgun with a barrel
length of less than 18 inches, or any weapon made from a shotgun or
rifle if, as altered, it has an overall length of less than 26
inches.
(11) "Switchblade knife" means any knife that has a
blade that folds, closes, or retracts into the handle or sheath, and
that:
(A) opens automatically by pressure applied to a
button or other device located on the handle; or
(B) opens or releases a blade from the handle or
sheath by the force of gravity or by the application of centrifugal
force.
(12) "Armor-piercing ammunition" means handgun
ammunition that is designed primarily for the purpose of
penetrating metal or body armor and to be used principally in
pistols and revolvers.
(13) "Hoax bomb" means a device that:
(A) reasonably appears to be an explosive or
incendiary device; or
(B) by its design causes alarm or reaction of any
type by an official of a public safety agency or a volunteer agency
organized to deal with emergencies.
(14) "Chemical dispensing device" means a device,
other than a small chemical dispenser sold commercially for
personal protection, that is designed, made, or adapted for the
purpose of dispensing a substance capable of causing an adverse
psychological or physiological effect on a human being.
(15) "Racetrack" has the meaning assigned that term by
the Texas Racing Act (Article 179e, Vernon's Texas Civil Statutes).
(16) "Zip gun" means a device or combination of
devices that was not originally a firearm and is adapted to expel a
projectile through a smooth-bore or rifled-bore barrel by using the
energy generated by an explosion or burning substance.