The Collaborative International Dictionary of English v.0.48:

Census \Cen"sus\, n. [L. census, fr. censere. See Censor.]
   1. (Bot. Antiq.) A numbering of the people, and valuation of
      their estate, for the purpose of imposing taxes, etc.; --
      usually made once in five years.
      [1913 Webster]

   2. An official registration of the number of the people, the
      value of their estates, and other general statistics of a
      country.
      [1913 Webster]

   Note: A general census of the United States was first taken
         in 1790, and one has been taken at the end of every ten
         years since.
         [1913 Webster]

WordNet (r) 3.0 (2006):

census
    n 1: a periodic count of the population [syn: census, nose
         count, nosecount]
    v 1: conduct a census; "They censused the deer in the forest"

Moby Thesaurus II by Grady Ward, 1.0:

105 Moby Thesaurus words for "census":
   account, accounting, accounts, agenda, assemblage, assembly,
   beadroll, body count, cadastre, calendar, call-up, canvass,
   capitulation, census report, checklist, checkroll, code,
   collection, colligation, collocation, combination, comparison,
   composition, concourse, concurrence, confluence, conflux,
   congregation, constituents, content, contents, convergence,
   corralling, count, counting, dactylonomy, data-gathering, digest,
   divisions, docket, dramatis personae, elements, enumeration,
   foliation, gathering, guts, head count, honor roll, index,
   ingathering, ingredients, innards, insides, inventory,
   inventorying, items, junction, jury list, jury panel,
   juxtaposition, lineup, list, measurement, mobilization, muster,
   muster roll, nose count, numbering, numeration, order of business,
   pagination, part, parts, poll, program, property roll,
   quantification, quantization, questionnaire, recapitulation,
   reckoning, recount, recounting, rehearsal, repertory, returns,
   rodeo, roll, roll call, roster, rota, roundup, scroll, statement,
   summary, summation, summing, summing up, survey, table,
   table of organization, tallying, tax roll, telling, whole



Easton's 1897 Bible Dictionary:

Census
   There are five instances of a census of the Jewish people having
   been taken. (1.) In the fourth month after the Exodus, when the
   people were encamped at Sinai. The number of men from twenty
   years old and upward was then 603,550 (Ex. 38:26). (2.) Another
   census was made just before the entrance into Canaan, when the
   number was found to be 601,730, showing thus a small decrease
   (Num. 26:51). (3.) The next census was in the time of David,
   when the number, exclusive of the tribes of Levi and Benjamin,
   was found to be 1,300,000 (2 Sam. 24:9; 1 Chr. 21:5). (4.)
   Solomon made a census of the foreigners in the land, and found
   153,600 able-bodied workmen (2 Chr. 2:17, 18). (5.) After the
   return from Exile the whole congregation of Israel was numbered,
   and found to amount to 42,360 (Ezra 2:64). A census was made by
   the Roman government in the time of our Lord (Luke 2:1). (See TAXING.)


Bouvier's Law Dictionary, Revised 6th Ed (1856):

CENSUS. An enumeration of the inhabitants of a country.
     2. For the purpose of keeping the representation of the several states
in congress equal, the constitution provides, that "representatives and
direct taxes shall be apportioned among the several states, which may be
included in this Union, according to their respective numbers; which shall
be determined by adding to the whole number of free persons, including those
bound to service for a term of years, and excluding Indians not taxed, three-
fifths of all other persons. The actual enumeration shall be made within
three years after the first meeting of the congress of the United States,
and within every subsequent term of ten years, in such a manner as they
shall by law direct." Art. 1, s. 2; vide 1 Story, L. U. S., 73, 722, 751; 2
Id. 1134, 1139, 1169, 1194; 3 Id. 1776; 4 Sharsw. continuation, 2179.