Green’s Dictionary of Slang

caper n.2

[SE caper, a frisky movement]

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

In compounds

caper cove (n.) [cove n. (1)]

[mid-19C] (US Und.) a dancing master.

caper juice (n.) [a sufficiency or an excess causes one to ‘cut capers’]

[19C] whisky.

caper merchant (n.) [merchant n.]

[late 18C–mid-19C] a dancing master.