from The American Heritage® Dictionary of the English Language, 5th Edition.

  • noun The ordinal number matching the number 18 in a series.
  • noun One of 18 equal parts.

from The Century Dictionary.

  • Next after the seventeenth: an ordinal numeral.
  • noun The quotient of unity divided by eighteen; one of eighteen equal parts of anything; an eighteenth part.
  • noun In music, an interval comprehending two octaves and a fourth.

from the GNU version of the Collaborative International Dictionary of English.

  • adjective Next in order after the seventeenth.
  • adjective Consisting of one of eighteen equal parts or divisions of a thing.
  • noun The quotient of a unit divided by eighteen; one of eighteen equal parts or divisions.
  • noun The eighth after the tenth.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

  • adjective The ordinal form of the number eighteen.
  • noun The person or thing in the eighteenth position.
  • noun One of eighteen equal parts of a whole.
  • noun informal A party to celebrate an eighteenth birthday.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • adjective coming next after the seventeenth in position
  • noun position 18 in a countable series of things


Sorry, no etymologies found.


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