Where does “tēman” come from?

tēman (Old English) comes from Proto-Germanic temaną, from Proto-Indo-European dem- — to build; to arrange, to put together.

Ancestry of “tēman”, step by step

Step	Language	Word	Meaning
1	Proto-Germanic	temaną	to fit
2	Proto-Indo-European	dem-	to build; to arrange, to put together

tēman — Etymology, Origin & Word History | Etymology Explorer