hīˈpēthrəl, hə̇ˈ- adjective
Etymology: Latin hypaethr us in the open air, uncovered (from Greek hypaithros, from hypo- + -aithros — from aithēr ether, heaven, air) + English -al — more at ether
1. of an ancient temple : having a roofless central space — opposed to cleithral
2. : open to the sky
3. : outdoor