Source : Free On-Line Dictionary of Computing

speculative evaluation
     
         A technique used in {parallel processing} where
        some evaluation may be started before it is known whether it
        is needed (Eager evaluation).  This may result in some wasted
        processing and may introduce unnecessary non-terminating
        processes but it can reduce the overall run time by making
        some needed results available earlier than they would be
        otherwise.
     
        Opposite: {conservative evaluation}.
     
        (1995-05-05)