Mid 17th century; earliest use found in John Ogilby (1600–1676), publisher and geographer. Apparently from lockspit (although this is first attested slightly later) + -ing.
Definition of lockspitting in US English:
lockspitting
nounˈlɒkspɪtɪŋ
The action of lockspit.
Origin
Mid 17th century; earliest use found in John Ogilby (1600–1676), publisher and geographer. Apparently from lockspit (although this is first attested slightly later) + -ing.