From Longman Dictionary of Contemporary Englishthe keythe keythe part of a plan, action etc that will make it possible for it to succeedthe key to Working well as a team is the key to success. a discovery that may hold the key to our understanding of the universe → key
Examples from the Corpus
hold the key• As James Brady knows, the patient himself holds the key to recovery.• Our journeys on the whiteboard suggest that it holds the key to our concepts of beauty.• Hidden layers hold the key to more complex computations.• Some threatened species have special qualities or abilities and may hold the key to undiscovered benefits.• The 38-year-old Berkeley grad may hold the keys to the engine.• Together or separately, the two of them may hold the key to power after the election.• Nor was the thought that he alone might hold the key to the mystery the sole component in his strangely elated state.• Police believe must hold the key to tracing the killers. 