Source : Webster's Revised Unabridged Dictionary (1913)

Pyla \Py"la\ n.; pl. L. {Pyl[ae]}, E. {Pylas}. [NL., fr. Gr. ?
   an entrance.] (Anat.)
   The passage between the iter and optoc[oe]le in the brain.
   --B. G. Wilder.