Related Finnish names are Kaleva and Kalevi.
Its meaning is most often "giant", "tall strong man".
The Russian word голова (golova), "head" as in "headman" has been suggested, but is linguistically anachronistic.
However, it could be Baltic (kalējs, "smith"), Finnic (kalea, "cool, hard") or Norse (Hlér, a sea god, from *xlewaz, or *xalewaz with an epenthetic vowel).
[1] People named Kalev include: