Dutch word langnek comes from Dutch lang, Dutch nek ((broad sense) Neck.. (narrow sense) Nape of the neck.)

Detailed word origin of langnek

Dictionary entry	Language	Definition
lang	Dutch (nld)	Long. Long (time), lengthy, a long time. Tall (with negation) by far.
nek	Dutch (nld)	(broad sense) Neck.. (narrow sense) Nape of the neck.
langnek	Dutch (nld)	(colloquial) giraffe. (colloquial) long-necked dinosaur, usually referring to sauropods.

Words with the same origin as langnek