Learn how to say Cracks correctly in English with this tutorial pronunciation video.
Oxford dictionary definition of the word crack:
to make a sudden, sharp noise, as of something breaking
to break or split, usually without complete separation of parts
to become harsh or rasping, as the voice when hoarse
to change suddenly from one register to another, as the voice of a boy in adolescence
(informal) to move with speed (now chiefly in phrase get cracking, to start moving with dispatch)
(informal) to break down ⇒ to crack under a strain