What is the meaning of Elve?

Obsolete form of elf.

A rapidly expanding disk-shaped region of red luminosity in the ionosphere, lasting less than a thousandth of a second, which occurs high above energetic cloud-to-ground lightning of positive or negative polarity.

third-person singular single-possession possessive of elv

high

to raise

to heighten

to bring up

Source: wiktionary.org