lookaheadn.adj.
/ˈlʊkəhɛd/, U.S. /ˈlʊkəˌhɛd/ A. n.
1. The action or an act of considering what is likely to happen, or of calculating what can happen, in the (immediate) future.In later use only in a computing context, and influenced by sense A. 2.
ΘΚΠ
the mind > mental capacity > expectation > foresight, foreknowledge > anticipation, forecast > [noun] > instance of
forethoughta1400
cast1519
forecasta1673
precalculation1841
calculation1848
lookahead1896
1896 T. Roosevelt Winning of West IV. i. 5 In questions of race supremacy the look-ahead should be for centuries rather than decades.
1973 Sci. Amer. June 93/3 Since the number of legal moves available to a player at each turn averages about 30, a full look-ahead to a depth of four would require examination of about 304, or 810,000 moves.
1984 E. Solomon Games Programming viii. 229 The method used for storing this data is intimately related to the manner in which the look-ahead is conducted.
2. Computing. More fully carry-lookahead. A method in computational arithmetic whereby the individual elements of an adder (adder n.2 3) are capable of determining when addition performed by preceding stages will generate output which has to be carried to subsequent stages; an implementation of this method. Frequently attributive.
ΚΠ
1959 Proc. Eastern Joint Computer Conf. 52/1 This carry look-ahead results in a delay time of 150 mμsec for 96-bit binary number additions.
1963 I. Flores Logic Computer Arithm. v. 83 Let us examine an adder which performs the carry function with a lookahead on several levels.
1971 IEEE Trans. Computers 20 863/1 The method of obtaining carries simultaneously using the well known technique for binary adders of carry look-ahead is easily extended.
1989 IEEE Jrnl. Solid-state Circuits 24 358/1 The use of the carry lookahead..principle..for high-speed arithmetic units remains dominant.
2002 G. R. Wilson Embedded Syst. & Computer Archit. iv. 60 Even though there are now several layers of look-ahead logic, this adder has a substantial advantage in speed of operation.
B. adj.
Of or relating to the action of calculating what can happen in the (immediate) future; designating something which does this.Apparently only in the context of computer design or technology. Cf. sense A. 2.
ΘΚΠ
the mind > mental capacity > expectation > foresight, foreknowledge > anticipation, forecast > [adjective]
forecasting1548
proleptical1611
proleptica1656
lookahead1959
1959 A. L. Samuel in IBM Jrnl. Res. & Devel. 3 214/1 [Draughts] Playing-time considerations make it necessary to limit the look-ahead distance to some fairly small value.
1967 A. Battersby Network Anal. (ed. 2) xii. 210 The effect of a ‘look ahead’ decision rule is shown.
2004 Keyboard Feb. 76/3 There's a lookahead feature that can be set to 0ms, 1ms, and 10ms, though 10ms adds a perceptible delay that can only be compensated for by inserting a simple delay on every other channel, thus limiting its usefulness somewhat.
This entry has been updated (OED Third Edition, March 2015; most recently modified version published online March 2022).
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n.adj.1896