Contrary to your repeated and explicit statements in this thread,
Ch. 140 §121 does
not constrain its definitions to
only be used in Ch. 140 §§122-131Y.
A counterexample:
MGL Ch. 265 §15E: Assault and battery by discharge of firearm, large capacity weapon, rifle, shotgun, sawed-off shotgun or machine gun; penalty
(a) Whoever commits an assault and battery upon another by discharging a firearm, large capacity weapon, rifle, shotgun, sawed-off shotgun or machine gun, as defined in section 121 of chapter 140, shall be punished by imprisonment in the state prison for not more than 20 years or by imprisonment in the house of correction for not more than 21/2 years or by a fine of not more than $10,000, or by both such fine and imprisonment.
Underscoring mine.
Ch. 265 §15E is plainly not contained within Ch. 140 §§122-131Y,
and yet Ch. 265 §15E uses the definitions of "firearm", etc. of Ch. 140 §121
even though Ch. 140 §121 makes no cross-reference to Ch. 265 §15E.
Perhaps your defense does not depend on that false assertion.
I'm completely uninterested in its details.
But you have to ask yourself,
"self, does my legal defense depend upon any
other false assertions?".
Non-existence proofs are difficult.
It's all fun and games until someone's bad case
generates bad case law which further disenfranchises us all.
(Shortened any shotgun barrels lately?)