What is the (closest) literal translation of que honda?

onda literally means wave. (without the h)

For example:
onda del mar - ocean wave
wavy hair - cabello ondulado

But ¿Qué onda? as a greeting etc, (used most commonly in Mexico) simply means What's up? / what's happening? / What's goin' down?

BTW, Welcome Tania :)

Thank you David!

No problem :)

Does honda with the h exist too? Or is it the car.

Does honda with the h exist too? Or is it the car.

I believe that honda means deep. For example, in the Florida Keys there is an island named Bahía Honda, which means deep bay.

Zach it's right.
"hondo/a" is deep.
"honda" can also be a sling, like the one in David & Goliath.
Look at Tomisimo's dictionary :D

OK Thank you.