Merriam-Webster's Collegiate® Dictionary, 11th Edition
PAVILION
I. noun
Etymology: Middle English pavilloun, pavillioun, from Anglo-French, from Latin papilion-, papilio butterfly; perhaps akin to Old High German fīfaltra butterfly
Date: 13th century
1. a large often sumptuous tent, something resembling a canopy or tent ,
2. a part of a building projecting from the rest, one of several detached or semidetached units into which a building is sometimes divided,
3. a usually open sometimes ornamental structure in a garden, park, or place of recreation that is used for entertainment or shelter, a temporary structure erected at an exposition by an individual exhibitor, the lower faceted part of a brilliant below the girdle,
II. transitive verb
Date: 14th century
to furnish or cover with or put in a pavilion