Where does “geranium” come from?

geranium (New Latin) comes from Ancient Greek γέρανος, from Proto-Indo-European ǵerh₂- — to grow old, to mature.

Ancestry of “geranium”, step by step

Step	Language	Word	Meaning
1	Ancient Greek	γέρανος	a crane, "Grus cinerea"; a crane; a type of dance
2	Proto-Indo-European	ǵerh₂-	to grow old, to mature