Hiram Maxim -- who invented them -- disagreed.
So did the patent bureau:
H. P. MAXIM SILENCER FOR GUNS Filed Feb. 21, 1921 Patented Feb. 5, 1924.
HIE/AM PERCY MAXIM, OF HARTFORD, CONNECTICUT. SILENCER FOR GUNS.
Application filed February 21, 1921. Serial No. 446,822.
T 0 all whom it may concern:
Be it known that I, HIRAM PERCY MAXIM, a citizen of the United States and a. resident of Hartford, county of Hartford, State of" Connecticut, have invented certain new and useful Improvements in a Silencer for Guns, of which the following is a specification. The present invention relates to a device for silencing the noise of a gun report, and ....
And so does today's BATFE: 
From the ATF Form 4 (5320. 4), Application for Tax Paid Transfer and Registration of Firearm, Revised November 2022
So Hiram says your wrong, the Patent Office says your wrong, and the BATFE says you're wrong.
The shorter answer is, it doesn't matter. call it a suppressor, a silencer, a muffler, a moderator or a 'can,' it's all the same thing. Even IF you convince everybody on earth NOT to call them silencers (like that's going to happen :roll eyes:), it's NOT going to get them off the list of NFA devices.