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Webster 1913 Edition

Adj.

[Cf. F.

nucal

(Anat.)

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.

nuchal ‎(plural nuchals)

nuchal ‎(not comparable)

Of or pertaining to the back or nape of the neck.
The patient showed no nuchal rigidity on examination.