>>I don't know what's the proper name for this category of words. The cases when one word from a phrase is taken out to mean the whole phrase, despite it having several uses outside of the phrase.
For symmetry, I've included a few oddly specific phrases, where an extra word is commonly added to denote the very important difference between the millions of instances of the common variant and the couple of exceptions.
a meat patty of Hamburg recipe, with the bun and toppings; actually, patty is not required, there's a cheese burger
because nobody knows what it is - a Hamburger means "the Hamburgian" - Hamburgian what?
Whoever invented this kind of vehicle, thought it was a good idea to advertise it as "for everybody" and took the latin "omnes" (all, everybody) but in dative case, "omnibus" (to everybody). Then everybody started pronouncing it abbreviated.
there are at least several other kinds of calculus - vector, numeric, celestial, difference and plain old calculus (aka arithmetics)
secret, for authorized personnel only
to classify means to split into classes, to assign each peace into a class; this was initially "classified as secret/confidential/sensitive" but was later abbreviated out of context.
nobody even remembers what it was that was commercial
anything that is plugged into a computer - disks, printers, floppies.
Made unforgettable by all those "device not ready" messages. The listener has to divine that it doesn't cover any devices not related to the computer (i.e. kitchen utensils, workshop tools etc).
This is newer - it's another computer which is not plugged into the computer on which it's mentioned, but connects to it wirelessly and can be used separately or in connection.
2nd phone line on the same number
There are also extension cords, fingernail extensions, filename extensions... Actually "phone line extension" was wrong from the start - every phone line is extended from point A to point B, so adding a few meters beyond point B doesn't change its nature and the extension line isn't different from the main line - they are parallel.
lights shining at wide angle, opposite of spotlight
flood is lots of water, "floodlight" is a somewhat poetic description
mother's milk replacement
Formula is a shorthand written expression in maths, physics chemistry. Usually describes a law of nature or a recipe for cooking up a compound.
"Baby formula", however, is not a recipe for "how to make a baby".
french fried potato
"Fry" could be anything fried, including electronics, fish, any steak.
Besides, it was invented by Belgians.
beaker, tumbler or any other similar vessel
Even when it's not made of glass - it could be plastic.
it's not a plural of glass (as a vessel or as a type of material)
truck with a hemi (2)
this is a bit recursive...
engine with a hemi (3)
recursive, I said
hemispheric combustion chamber
Now roll it back
Because the language never bothered to invent a word for this utensil, so it kept the name of the element for it. And it is mostly not made of iron nowadays. Interestingly, many other languages have the word.
i.e. the url to which to go AFTER logout, not the url to go to log out (which usually doesn't really exist, or if it does, doesn't show itself but redirects elsewhere).
There are thousands of things which are military by nature or origin or by design, but when this adjective is used as a noun (and not as "the military one" like most such adjectives become nouns), then it actually means the army.
Fancy name for an operetta, which probably sounded too posh and foreign for the audience, so it was named "musical comedy", and nowadays after decades of development in its own direction, it's yet another contextless adjective-cum-noun.
the crude mineral oil
because they were too lazy to import some word for it (and it exists in other languages)
painting done with oil colors
mentioning the canvas is optional
word pool has at least two other prominent meanings; to make things worse, many players of pool don't even know the word billiard
there's also a promotion in any hierarchy, promotion in chess, or simply the act of awarding the title to a graduate
Because, in history, there were a few cases when pilaf was made of wheat. So state million times that this is not the case.
So the whole gun is called after the helicoidal groove in the bore. Rifle is a gun with rifled bore.
safety lock on a weapon
safety has a dozen other meanings
a truck designed to pull a half-trailer
...Which is not really a half of anything, just doesn't have a front axle. "Semi" is actually a prefix meaning "half".
static electricity discharge noise; also any noise disturbing communications
static is anything that isn't moving; this noise only originates in the statically charged things but it is motion by itself.
stereo sound system
They usually mean the home or car sound system, but there are so many other things which are stereo(-phonic or -scopic), like all 3d movie and/or video systems, binoculars, printed stereographic images... all of them stereo.
This is not any kind of sandwich that was invented on, or served on, submarines. The bun resembles a submarine by shape, just as much as it resembles a cucumber or a cigar or a blimp.
landing strip for flying vehicles
It used to mean "tar and macadam", the latter being the gravel laid by MacAdam's recipe. It's a precursor to asphalt. The runways are mostly just concrete, so even the mention of tar is misplaced.
This is even funnier when SF writers mention tarmac on other planets.
Same word is used for television as a system, and sometimes for a television station. That's confusing.
thumbnail sized image
Thumb is still the part of your hand with which you press the spacebar, not a silly image file.
now try to wipe your hands with some muscle tissue... or neural
vacuum cleaner; clean using vacuum cleaner
Vacuum is utter void, no air, no pressure. Saying "vacuum" to denote some sub-pressure is like calling any fraction a zero.
Besides, vacuum is not dirty at all, it needs no cleaning.
because it is made of vinyl plastic; to differ from all other items made from same plastic, and from all other types of records made on other media