Term of art
A term of art is a word or phrase that is in common use, but, in a particular context, has a precise meaning. It is the antithesis of jargon, where an uncommon word or phrase is used to describe something very specific, but where the jargon term is incomprehensible outside the area of use. Terms of art and jargon sometimes are characterized as different forms of slang."Term of art" probably first came into use in law.  Random House makes the nuanced distinction that "art" is not used as in "artist", but as the specialized usage of an "artisan's" vocabulary.
An ordinary technical term for which there is no other word or phrase is not a term of art. That criterion would exclude "CPU" and "RAM" in the computer field and "Phillips screwdriver" in carpentry. But fields other than the law do have terms of art. Using these terms consistently makes it easier for members of the same field--the in-group--to understand one another. For example, according to Random House Webster's Unabridged Dictionary, "blanch," commonly 'to whiten', is a term of art with particular meanings in horticulture, metallurgy, and cooking. But only a pathologist would be likely to recognize a "nutmeg" liver or a "chicken-fat" clot.