1. nuchal - Noun
2. nuchal - Adjective
Of, pertaining to, or in the region of, the back, or nape, of the neck; -- applied especially to the anterior median plate in the carapace of turtles.
Source: Webster's dictionaryIn the Phascolosomatidea, the tentacles are arranged in an arc around the nuchal organ, also located at the tip of the introvert. Source: Internet
It is sometimes diagnosed prenatally by a nuchal scan or post-natally by lymphoscintigraphy. Source: Internet