decimal

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

• noun A linear array of digits that contains a single period, called the decimal point, is possibly preceded by a minus sign (−), and represents a real number, with each successive digit to the right of the decimal point indicating a multiple of the next negative power of 10, and each successive digit to the left of the decimal point indicating a multiple of the next non-negative power of ten, beginning with 10⁰ = 1. For example, 245.3 represents the real number (2 × 10²) + (4 × 10¹) + (5 × 10⁰) + (3 × 10⁻¹) = 200 + 40 + 5 + ³/₁₀ , and −1.04 represents the real number (−1 × 10⁰) + (−4 × 10⁻²).
• noun Such an array of digits in which there are no nonzero digits to the left of the decimal point, representing a real number between −1 and 1.
• noun A number written using the base 10.
• adjective Expressed or expressible as a decimal.
• adjective Based on 10.
• adjective Numbered or ordered by groups of 10.

from The Century Dictionary.

• Of an angle, one sixtieth of a right angle.
• Of an arc, one two-hundred-and-fortieth of a circumference.
• Of time, 0.01 of an hour; 0.6 of an ordinary minute.
• Pertaining to the tenth or to tens; proceeding by tens.
• Relating to tithes.
• noun An expression denoting a decimal fraction by an extension of the decimal notation.

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

• adjective Of or pertaining to decimals; numbered or proceeding by tens; having a tenfold increase or decrease, each unit being ten times the unit next smaller
• adjective the common arithmetic, in which numeration proceeds by tens.
• adjective a fraction in which the denominator is some power of 10, as 2/10, 25/100, and is usually not expressed, but is signified by a point placed at the left hand of the numerator, as .2, .25.
• adjective a dot or full stop at the left of a decimal fraction. The figures at the left of the point represent units or whole numbers, as 1.05.
• noun A number expressed in the scale of tens; specifically, and almost exclusively, used as synonymous with a decimal fraction.
• noun a decimal fraction in which the same figure, or set of figures, is constantly repeated; as, 0.354354354; -- called also recurring decimal, repeating decimal, and repetend.

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

• noun arithmetic, computing, uncountable The number system that uses the digits 0, 1, 2, 3, 4, 5, 6, 7, 8 and 9.
• noun countable A number expressed in this system.
• noun informal A decimal place.
• noun informal A numeral written as a concatenation of successive negative powers of the base.
• noun informal A decimal point.
• adjective arithmetic, computing Concerning numbers expressed in decimal or mathematical calculations performed using decimal.

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

• adjective numbered or proceeding by tens; based on ten
• noun a number in the decimal system
• noun a proper fraction whose denominator is a power of 10