1 example sentence using guideword.
Guideword used in a sentence
Guideword in a sentence as a noun
In the same sense that the choice of how to paginate a phone book and where to put the guidewords on each page is copywritable, yes APIs are copyrightable.
Guideword definitions
noun
a word printed at the top of the page of a dictionary or other reference book to indicate the first or last item on that page
See also: catchword