idempotent
         adj 1: unchanged in value following multiplication by itself;
                  "this matrix is idempotent"

English Dictionary: item-by-item	by the DICT Development Group
From WordNet (r) 3.0 (2006) [wn]:
item-by-item adj separate and distinct from others of the same kind; "mark the individual pages"; "on a case-by-case basis" Synonym(s): individual, case-by-case, item-by-item
From Webster's Revised Unabridged Dictionary (1913) [web1913]:
May \May\, v. [imp. {Might}] [AS. pres. m[91]g I am able, pret.       meahte, mihte; akin to D. mogen, G. m[94]gen, OHG. mugan,       magan, Icel. mega, Goth. magan, Russ. moche. [?]. Cf.       {Dismay}, {Main} strength, {Might}. The old imp. mought is       obsolete, except as a provincial word.]       An auxiliary verb qualifyng the meaning of another verb, by       expressing:       (a) Ability, competency, or possibility; -- now oftener             expressed by can.                         How may a man, said he, with idle speech, Be won to                      spoil the castle of his health !      --Spenser.                         For what he [the king] may do is of two kinds; what                      he may do as just, and what he may do as possible.                                                                               --Bacon.                         For of all sad words of tongue or pen The saddest                      are these: [bd]It might have been.[b8] --Whittier.       (b) Liberty; permission; allowance.                         Thou mayst be no longer steward.      --Luke xvi. 2.       (c) Contingency or liability; possibility or probability.                         Though what he learns he speaks, and may advance                      Some general maxims, or be right by chance. --Pope.       (d) Modesty, courtesy, or concession, or a desire to soften a             question or remark.                         How old may Phillis be, you ask.      --Prior.       (e) Desire or wish, as in prayer, imprecation, benediction,             and the like. [bd]May you live happily.[b8] --Dryden.          {May be}, [and] {It may be}, are used as equivalent to             possibly, perhaps, by chance, peradventure. See 1st             {Maybe}.
From Webster's Revised Unabridged Dictionary (1913) [web1913]:
Phono \Phono\, n. (Zo[94]l.)       A South American butterfly ({Ithonia phono}) having nearly       transparent wings.
From U.S. Gazetteer (1990) [gazetteer]:
Itawamba County, MS (county, FIPS 57)       Location: 34.27772 N, 88.35905 W       Population (1990): 20017 (8116 housing units)       Area: 1378.9 sq km (land), 20.9 sq km (water)
From Jargon File (4.2.0, 31 JAN 2000) [jargon]:
idempotent adj.   [from mathematical techspeak] Acting as if    used only once, even if used multiple times.   This term is often    used with respect to {C} header files, which contain common    definitions and declarations to be included by several source files.    If a header file is ever included twice during the same compilation    (perhaps due to nested #include files), compilation errors can    result unless the header file has protected itself against multiple    inclusion; a header file so protected is said to be idempotent.   The    term can also be used to describe an initialization subroutine that    is arranged to perform some critical action exactly once, even if    the routine is called several times.
From The Free On-line Dictionary of Computing (15Feb98) [foldoc]:
Id Nouveau          A {dataflow} language by Arvind and       R.S. Nikhil , {MIT} {LCS}, ca. 1986.          Id Nouveau began as a {functional language}, added {stream}s,       resource managers and {I-structure}s ({mutable array}s).       Loops are {syntactic sugar} for {tail recursion}.          See also {Id}.          ["Id Nouveau Reference Manual", R.S.   Nikhil, CS TR, MIT,       March 1988].          ["Id (Version 90.1) Reference Manual", R.S. Nikhil, CSG Memo       284-2, LCS MIT, July 15, 1991].
From The Free On-line Dictionary of Computing (15Feb98) [foldoc]:
idempotent          1. A function f : D -> D is idempotent if          f (f x) = f x   for all x in D.          I.e. repeated applications have the same effect as one.   This       can be extended to functions of more than one argument,       e.g. Boolean & has x & x = x.   Any value in the {image} of an       idempotent function is a {fixed point} of the function.          2. This term can be used to describe {C} header files, which       contain common definitions and declarations to be included by       several source files.   If a header file is ever included twice       during the same compilation (perhaps due to nested #include       files), compilation errors can result unless the header file       has protected itself against multiple inclusion; a header file       so protected is said to be idempotent.          3. The term can also be used to describe an initialisation       subroutine that is arranged to perform some critical action       exactly once, even if the routine is called several times.          [{Jargon File}]          (1995-01-11)