Source : Webster's Revised Unabridged Dictionary (1913)

Summerhouse \Sum"mer*house`\, n.; pl. {Summerhouses}.
   A rustic house or apartment in a garden or park, to be used
   as a pleasure resort in summer. --Shak.

Source : WordNet®

summerhouse
     n : a small roofed building affording shade and rest [syn: {gazebo}]