Example: "The key to development is economic integration"
Example: "He spoke in a low key"
Example: "They were carrying two keys of heroin"
Example: "He hit a jump shot from the top of the key"
Example: "Some students had stolen the key to the final exam"
Example: "A safe-deposit box usually requires two keys to open it"
Example: "A cardinal rule"
Example: "We were keyed after the locks were changed in the building"
Example: "His new mercedes was keyed last night in the parking lot"
Example: "Key one's actions to the voters' prevailing attitude"