"Heim" is German for "home." It’s a noun (das Heim, meaning a home or dwelling) and an adverb (heim, meaning "homeward"), and it traces back to the Proto-Germanic root haimaz — the same root that gives English the word "home."
The Word, Beyond German
The root shows up across the Germanic language family, not just in German. Norwegian, Icelandic, and Faroese all use heim to mean "home." It’s also the source of the familiar German place-name suffix -heim — seen in city names like Mannheim and Hildesheim, and carried into English via towns like Anaheim — which functions the same way the English suffix "-ham" does in names like Birmingham: it marks a settlement or dwelling place. Beyond place names, Heim is also a common surname of German, Norwegian, and Ashkenazi Jewish origin.
Why This Word Shows Up on a Rod End
None of that etymology is why the part in your hand is called a "Heim joint," though. As covered in What Exactly Is a Heim Joint?, the name comes from the Heim Company, the manufacturer that patented the spherical rod end design during World War II to solve an aircraft control-linkage problem. In that context, "Heim" is a surname/company name, not a literal reference to "home" — a distinction worth making so the etymology doesn’t get read as some kind of engineering metaphor. It’s a trademark-turned-generic-term, the same pattern as calling any tissue a "Kleenex."
Related reading: What Exactly Is a Heim Joint?
