splenius
Concise Oxford English Dictionary © 2008 Oxford University Press:
splenius /ˈspliːnɪəs/
▶noun (pl. splenii /-nɪʌɪ/) Anatomy either of two muscles attached to the vertebrae in the neck and upper back which draw back the head.
– origin C18: mod. L., from Gk splēnion ‘bandage’.
'splenius' also found in these Oxford entries:

