Significant decline in economic activity spread across the economy, lasting more than a few months, normally visible in real gross domestic product, real income, employment, industrial production, and wholesale-retail sales. (National Bureau of Economic Research, Inc, www.nber.org/cycles.html, accessed 4/23/2009)

The science of utilization, distribution, and consumption of services and materials.

The state of not being engaged in a gainful occupation.

Exposure of the root surface when the edge of the gum (GINGIVA) moves apically away from the crown of the tooth. This is common with advancing age, vigorous tooth brushing, diseases, or tissue loss of the gingiva, the PERIODONTAL LIGAMENT and the supporting bone (ALVEOLAR PROCESS).