crack

noun:a line on the surface of something along which it has split without breaking into separate parts
- A small crack appeared in the plaster on the ceiling.
noun:a sudden, sharp sound
- We heard the crack of a branch breaking under the weight of the snow.
noun:a joke or a clever, often sarcastic remark
- He couldn't resist making a crack about her new haircut.
verb:to find the solution to a problem or puzzle
- The detective finally managed to crack the code.
verb:to lose control of one's emotions or composure under pressure
- After hours of questioning, the suspect began to crack.
adjective:very good, skillful, or efficient
- The company hired a crack team of engineers to solve the problem.