From Netflix's show Voltron: Legendary Defender, "Vrepit Sa" is a salute of the Galra, which is revealed to be a saying of their people, meaning "Killing Stroke".
The origin of the term comes from an ancient war in which the Galra prevailed by using a strategy of picking the best men and executing a swift and deadly attack, naming it the killing stroke.
Zarkon: This news is most pleasing. You have done your duty. Vrepit Sa!
Sendak: Vrepit Sa!
In the Netflix animated show "Voltron-Legendary Defender", the Galra soldiers say "Vrepit Sa". The meaning has been disputed but it is safe to assume it means "Onward". It is a saying with Slovak origins. It's the equivalent to the US Army "Hooah" or the US Marine Corp "Hoorah".
Haggar: Make sure that no one disturbs my ritual.
Galra Soldiers: Vrepit Sa.
Means «Killing Thrust», it's used by the Galra soldiers as salute.
Do you understand?
Yes, vrepit sa.
Galra soliders or commanders say "vrepit sa" as a salute.
From Voltron Legendary Defenders
"Do you understand?"
"Yes, vrepit sa."