from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A transitional zone between two communities containing the characteristic species of each.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. a transition area between two adjacent ecological communities (ecosystems).
from The Century Dictionary and Cyclopedia
- n. In phytogeography, the line along which two types of vegetation compete for the same ground. See tension-line.
eco- + Greek tonos, tension, tone; see tone.(American Heritage® Dictionary of the English Language, Fourth Edition)
Combination of eco- (“ecology”) + -tone, from the Greek τόνος (tonos, "tension"). (Wiktionary)