Meaning of wagon-headed

wag•on-head•ed

Pronunciation: (wag'un-hed"id), [key]
— adj. Archit.
  1. of the form of a round arch or a semicylinder, like the cover of a wagon when stretched over the bows, as a ceiling or roof.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.