I have a Bausch & Lomb publication from 1932. It uses the term "photographic lenses".
I also have a Carl Zeiss publication dated 1938 (in English). It uses the term "photographic objectives".

Now what is the proper name (or as I learned in the Army over 40 years ago, "nomenclature") for the front and back parts of your typical large format photographic lens/objective. That what screws in to the front and back of the shutter or in the case of a barrel mount, into the barrel fore and aft of the diaphragm, and which in the case of a convertible lens/objective, constitutes a discrete lens/objective in itself? Component? Cell? Thingy?
David