from The American Heritage® Dictionary of the English Language, 4th Edition
- n. Mathematics The symbol (+), as in 2 + 2 = 4, that is used to indicate addition or a positive quantity.
- n. Chemistry The same symbol, used to indicate dextrorotatory rotation of polarized light.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. The symbol + used to denote the operation of addition and to indicate that a number is positive.
from the GNU version of the Collaborative International Dictionary of English
- adj. the sign (+) which denotes addition, or a positive quantity.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. a sign indicating the operation of addition
Sorry, no etymologies found.
Darlington used symbols a plus sign for normal wings, a minus sign for shrunken to designate wing morphology, but for our purposes it’s as easy to talk about full-winged and shrunken-winged species.