¹ crack verb

• to break (something) so that there are lines in its surface but it is usually not separated into pieces
• to hit or press (something) so hard that it breaks apart or opens suddenly
• to hit (someone or something) hard and usually suddenly

² crack noun

• a thin line in the surface of something that is broken but not separated into pieces —often + in
• a very narrow space or opening between two things or two parts of something
• a sudden loud, sharp sound—usually singular

³ crack adjective

• very good : of excellent quality or ability