Where does “foster” come from?

foster (Swedish) comes from Old Norse fóstr, from Proto-Germanic fōstrą, from Proto-Indo-European peh₂- — to protect; to shepherd.

foster (Swedish): fetus

Definitions

Step	Language	Word	Meaning
1	Old Norse	fóstr	rear, raise; nurturing, education, alimony, child...
2	Proto-Germanic	fōstrą	fostering
3	Proto-Indo-European	peh₂-	to protect; to shepherd

foster — Etymology, Origin & Word History | Etymology Explorer