WordNet (r) 3.0 (2006):

business cycle
    n 1: recurring fluctuations in economic activity consisting of
         recession and recovery and growth and decline [syn:
         business cycle, trade cycle]

Moby Thesaurus II by Grady Ward, 1.0:

25 Moby Thesaurus words for "business cycle":
   boom, bottoming out, business fluctuations, bust, cooling off,
   crisis, depression, downturn, economic cycle, economic expansion,
   economic growth, expanding economy, expansion, growth,
   high growth rate, low, market expansion, peak, peaking, prosperity,
   recession, recovery, slowdown, slump, upturn