Green’s Dictionary of Slang

larkery n.

[lark v. (1)]

playfulness (whether rough or gentle).

[UK]Egan Boxiana I 9: The late Lord B— [...] about the year 1789 was in the very zenith of his fun, frolic, and lark-ery.
[UK]Cheshire Obs. 20 Nov. 6/6: Horsery, Schoolary, Larfkery, Dealery. A nice ‘Savage’ young man.