A house or dwelling built in the branches of a tree. (noun)
The Century Dictionary (Public Domain)
Use "tree-house" in a sentence
"Micheline and Didi are fox cubs who live with their parents, Monsieur et Madame Renard, in a comfortable, middle-class, three-storey tree-house with hammock."
"Picking his way through the contested territory, Mr. Richetto removed a No TAV banner from his backpack and handed it to a fellow villager who climbed up a rope ladder to a towering tree-house and hung the flag."
"It wasn't London or Paris or Alex's tree-house or Piedmont or Vancouver or the wood's behind her uncle's house or Madeline's party or Clarke..."