Few trees called "cedar" are in the Cedrus genus. To be fair many of these were called a type of "cedar" before the Cedrus genus was even coined. Cedar really just means "a really good tree" (for woodworking)
Again, what is and isn't a "true cedar" is a silly debate. Some of these trees were called cedars before Cedrus was even coined. Junipers and even citrus were called cedars long before Linnaeus came along. It really got applied to any tree that had scented, rot-resistant wood
I'm not caring so much about the Cedrus genus, as the dilution of the word through unimaginative overuse and over-application. But to the extent that it still means anything at all, I would say it means an aromatic evergreen, since those are the two traits that seem to unite all the various trees colloquially referred to as cedars.
