Syn"co*pe (?), n. [L. syncope, syncopa, Gr. a cutting up, a syncope; akin to to beat together, to cut up, cut short, weavy; with + to strike, cut.]
* In music, the displacement of regular accents associated with given metrical patterns, resulting in a disruption of the listener's expectations and the arousal of a desire for the reestablishment of metric normality; hence the characteristic "forward drive" of highly syncopated music. Syncopation may be effected by accenting normally weak beats in a measure, by resting on a normal accented beat, or by tying over a note to the next measure.
The pattern is typical of much folk-dance music, especially in eastern Europe, and its use in the Western written tradition may be traced to the 14th century. It is a characteristic element of jazz and figures prominently in the music of Igor Stravinsky and other 20th-century composers.
The position of notes in a bar show their relative rhythmic strengths. However, occasionally, the rhythmic pattern wanted does not fit the rhythmic pattern shown by the barring. One says that the rhythm is 'off the beat' or syncopated. Examples of this are common in popular music including jazz, but it does occur in music of all ages. We have given a good example of syncopation below. Note, in particular, the theme played by pianist's right hand (the upper line of the piano part). The theme is 'off the beat' for much of the time, i.e. it is syncopated. The 'effect' is notated using ties. A crucial feature of syncopation is that there should be a strong sense of the beat 'off which' the theme is being played. This is provided by the percussion and bass guitar lines. --"Syncopation." Encyclopędia Britannica. 2003.
There is a second type of syncopation, where the strong beat is replaced by a silence. http://www.dolmetsch.com/musictheory20.htm
* In medicine, the temporary loss of consciousness due to a sudden decline in blood flow to the brain. It may be caused by an irregular cardiac rate or rhythm (the heart doesn't pump a normal supply of oxygen to the brain) or by changes of blood volume or distribution(hypotension). http://www.wrongdiagnosis.com/artic/ninds_syncope_information_page_ninds.htm
Despite intensive investigation syncopal attacks often remain unexplained. (http://libarynth.f0.am/cgi-bin/twiki/view/Libarynth/ProjectSyncoptic)
Syncopation in Music and Dance By Philip Seyer