from The American Heritage® Dictionary of the English Language, 4th Edition
- n. Medical therapy involving exposure to sunlight.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. Any medical therapy by exposure to light.
from The Century Dictionary and Cyclopedia
- n. Treatment of disease by means of sunlight: a form of phototherapy.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. therapeutic exposure to sunlight
helio- + therapy (Wiktionary)