A chaise longue is a long chair: long enough to sit back and recline in. If you want to take a nap, a chaise longue is just about perfect.
This French word has often been misspelled and mispronounced, because it looks so much like chase lounge, and it is the kind of furniture made for lounging. However, the original and correct spelling comes direct from French: chaise longue, which literally means long chair: exactly what it is. A chaise longue is like a recliner, and it can also be called a chaise or a daybed.