from The American Heritage® Dictionary of the English Language, 4th Edition
- n. Time regarded as a coordinate dimension and required by relativity theory, along with three spatial dimensions, to specify completely the location of any event.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. The fourth coordinate indicating a position along the fourth axis.
- n. The dimension of time.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. the fourth coordinate that is required (along with three spatial dimensions) to specify a physical event
Sorry, no etymologies found.