A newish word (created in the late 1950s) for an old subject, and possibly a new topic of discussion on this blog, vexillogogy is the study of flags.
It is also an example of words that are half latin/half greek hybrids. Other examples include meritocracy, homosexuality, television, metadata, and sociopath. There’s a long list on Wikipedia, because of course there is, and it is not limited to Greek/Latin mash-ups. Er, hybrids. Although almost every example on the list is a Greek/Latin example. I haven’t checked that entire list though, so the ordinary caveats about things on the internet apply.