from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A group or series of seven.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. a group of seven things
from the GNU version of the Collaborative International Dictionary of English
- n. An atom which has a valence of seven, and which can be theoretically combined with, substituted for, or replaced by, seven monad atoms or radicals. Also used as an adjective.
from The Century Dictionary and Cyclopedia
- n. The sum of seven units; the number seven.
- n. In chem., an atom whose equivalence is seven atoms of hydrogen, or which can be combined with, substituted for, or replaced by seven atoms of hydrogen.
- n. In music, in the duodenal system of analysis, a scheme of seven tones, formed by uniting two duodenal cells of four tones.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. the cardinal number that is the sum of six and one
Greek heptas, heptad-, the number seven, from hepta, seven; see septm̥ in Indo-European roots.(American Heritage® Dictionary of the English Language, Fourth Edition)
hepta- + -ad (Wiktionary)