An emotion directed to the attainment of some object from which pleasure or satisfaction is expected. Desire therefore has three elements critical to it: (1) an external object, (2) a feeling directed to the attainment of satisfaction from that object and (3) an internal (subjective) reward or satisfaction.
Kawabata, H., & Zeki, S. (2008). The neural correlates of desire. PLoS One, 3(8), e3027. doi: 10.1371/journal.pone.0003027.