Wiktionary
tree tent
n. A camping tent that is designed to be used above the ground and is usually attached to or supported by the neighbouring trees.
Wikipedia
Tree tent
A tree tent is a camping tent designed to be set above the ground, usually attached to or supported by the neighboring trees. Like a tent, it must be a complete enclosure that can house a camper and his or her gear while suspended off the ground. Like tree houses, a tree tent may be accessed via a rope ladder and provide a sheltered environment for recreation and various outdoor activities. The portable nature of this type of shelter provides for more versatile location choice than a conventional tree house or a camping tent.