"Take your orni and fly due south-west."
I heard this quote in a dialogue from the game "Dune" and I am wondering if the usage of "due" is applicable in this case.
In your example sentence due is used as an adverb. According to The Free Dictionary, definition #1, as adverb, it means straight, directly.
- Straight; directly: Go due west.
"Due" in this case means "exactly". That is "due southwest" means to travel at 225 degrees (if north is 0).