De*cid"u*ous (?; 135), a. [L. deciduus, fr. dec&?;dere to fall off; de- + cadere to fall. See Chance.] (Biol.) Falling off, or subject to fall or be shed, at a certain season, or a certain stage or interval of growth, as leaves (except of evergreens) in autumn, or as parts of animals, such as hair, teeth, antlers, etc.; also, shedding leaves or parts at certain seasons, stages, or intervals; as, deciduous trees; the deciduous membrane.
De*cid"u*ous*ness, n. The quality or state of being deciduous.
{ Dec"i*gram, Dec"i*gramme } (?), n. [F. décigramme; pref. déci- tenth (fr. L. decimus) + gramme.] A weight in the metric system; one tenth of a gram, equal to 1.5432 grains avoirdupois.
{ Dec"il, Dec"ile } (?), n. [F. décil, fr. L. decem ten&?; cf. It. decile.] (Astrol.) An aspect or position of two planets, when they are distant from each other a tenth part of the zodiac, or 36°.
{ Dec"i*li`ter, Dec"i*li`tre } (?), n. [F. décilitre; pref. déci- tenth (L. decimus) + litre. See Liter.] A measure of capacity or volume in the metric system; one tenth of a liter, equal to 6.1022 cubic inches, or 3.38 fluid ounces.
De*cil"lion (?), n. [L. decem ten + the ending of million.] According to the English notation, a million involved to the tenth power, or a unit with sixty ciphers annexed; according to the French and American notation, a thousand involved to the eleventh power, or a unit with thirty-three ciphers annexed. [See the Note under Numeration.]
De*cil"lionth (?), a. Pertaining to a decillion, or to the quotient of unity divided by a decillion.
De*cil"lionth (?), n. (a) The quotient of unity divided by a decillion. (b) One of a decillion equal parts.
Dec"i*mal (?), a. [F. décimal (cf. LL. decimalis), fr. L. decimus tenth, fr. decem ten. See Ten, and cf. Dime.] 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; as, decimal notation; a decimal coinage.
Decimal arithmetic, the common arithmetic, in which numeration proceeds by tens. -- Decimal fraction, a fraction in which the denominator is some power of 10, as , , and is usually not expressed, but is signified by a point placed at the left hand of the numerator, as .2, .25. -- Decimal point, 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.
Dec"i*mal, n. A number expressed in the scale of tens; specifically, and almost exclusively, used as synonymous with a decimal fraction.
Circulating, or Circulatory, decimal, 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.
Dec"i*mal*ism (?), n. The system of a decimal currency, decimal weights, measures, etc.
Dec"i*mal*ize (?), v. t. To reduce to a decimal system; as, to decimalize the currency. -- Dec`i*mal*i*za"tion (#), n.
Dec"i*mal*ly, adv. By tens; by means of decimals.
Dec"i*mate (?), v. t. [imp. & p. p. Decimated (?); p. pr. & vb. n. Decimating (?).] [L. decimatus, p. p. of decimare to decimate (in senses 1 & 2), fr. decimus tenth. See Decimal.] 1. To take the tenth part of; to tithe. Johnson.
2. To select by lot and punish with death every tenth man of; as, to decimate a regiment as a punishment for mutiny. Macaulay.
3. To destroy a considerable part of; as, to decimate an army in battle; to decimate a people by disease.
Dec`i*ma"tion (?), n. [L. decimatio: cf. F. décimation.] 1. A tithing. [Obs.] State Trials (1630).