The story
- Dutch · derived fromvader“father”
- English todayDarth Vader
"Darth" is a blend of dark + death (the derivation from Dark Lord of the Sith is a later development). "Vader" is traditionally explained as being from Dutch vader (“father”). However, Vader was not a literal father until The Empire Strikes Back (after the character was introduced), making this explanation more dubious than it may initially seem. This leaves a few possibilities. One is that it is still derived from “father,” but from a larger phrase “dark father,” where “dark” supports a figurative reading of “father” that alludes to absolute power rather than literal paternity. Were that so, this internal codename could even be an inspiration for the later idea of Darth Vader’s literal paternity over Luke. Another possibility is that it is a shortening of invader, or that it is derived from the surname Vader. Note that these above etymologies are not necessarily mutually exclusive, since names of characters in fiction are often compositions of various terms designed to evoke a certain sentiment.
Etymology from Wiktionary, CC BY-SA 4.0.