1. [mid-19C+] (also caperanie, caperings) a dodge, a trick.
2. [mid-19C+] a situation, an event.
3. [late 19C+] (mainly US) an occupation, a job.
4. [late 19C+] the proper course of action; esp. ext. as the proper caper, the right thing to do.
5. [1920s+] a large-scale crime, usu. involving a great deal of elaborate planning and aimed at very large sums of money, expensive pieces of jewellery etc; the supposed lack of violence in such enterprises lent them a somewhat ‘jokey’ air.
6. [1920s+] a crime, irrespective of scale.
7. [1950s+] a scheme.
8. [1950s] an affair.
9. [1960s] (N.Z.) a thing, an object.
SE in slang uses
[mid-19C] (US Und.) a dancing master.
[late 18C–mid-19C] a dancing master.