When you crack open an introductory book on kinship words in Proto-Indo-European, you get the surface. You find the words for father and mother and some interesting descriptions of the intensely patriarchal, inherently patrilineal stratification to Indo-European society. But borrowing a page from yesterday's post, kinship terms are very ancient and they often contain extremely old vestiges from even older words. Words that had already disappeared by the time of Proto-Indo-European proper (~4500 BCE), but survived as cranberry morphemes. Hey, that's where the name of my site comes from! Let's take a look at some of these deep water survivors:
*ḱur- "male?" Hidden as a suffix in *su̯e-ḱur- "father-in-law." It probably post-dates the departure of Anatolian, but must be old enough to participate in the *su̯e- kinship words. A derivationally close cognate is *su̯e-ḱur-o- "brother-in-law." The word could be feminized to "woman" through the use of suffixes or by changing the gender to female, but this was likely a later innovation. There is also a verbal root *kur- "birth" that is attested in Indo-Iranian languages (and possibly Hittite kurka- and Armenian k'uṙak "foal" and Greek κύρνος "bastard"), which leads one to wonder if both *kur- and *ḱur- are related but the difference between *k and *ḱ is difficult to resolve. Armenian k'uṙak points to *ḱ, a *ḱ would yield *s in Sanskrit yet we see kúla "household".
*h2en- "female," "male?" Found in many reflexes that point to *h2en-Ho-. While the majority of instances indicate a female, there are plenty of male words to go around as well. The Anatolian branch springs for female: Hittite ḫanna and Lycian χñna- both mean "grandmother." Other branches are less convincing. Armenian han means "old woman" but then a derivational form aner means "father-in-law." *h2en- is found in Greek ἀννίς "grandmother."
*ḱoi- "fellow" The first element in many reflexes but never appears on its own. *ḱoi(H)-no- "kinsman" and a root extension *ḱeiH- "wedding" and *ḱeiH-u̯o- with a less clear original semantic sense (only attested in Sanskrit śéva- "friendly."
Of course, there are many other suffixes, stems, and prefixes that could be adduced from a full study of Indo-European kinship terms, but what I attempted to do where was divine some of the most ancient - the ones deeply hidden. Most lexical items found in kinship terms are well discussed. Sergey Kulland's Indo‐European “Kinship Terms” Revisited is a very good resource for the much-discussed bits and pieces.