Definition of crack:
		
		
		(n) :
		
		a thin and usually 
jagged space opened in a previously solid material; a narrow opening
		
 
								
				"a large crack had formed in the roadway."
			
			
	
		
		
		(v) :
		
		to form cracks; to break apart under pressure
		
								
				"it's been so dry, the ground is starting to crack."
			
			
	
		
								
				"even a crack team of investigators would have trouble solving this case."