Green’s Dictionary of Slang

of an unwanted child, to dispose of to get rid of .

1866

Sportsman 22 Sept. 2/1: Notes on News [...] Conseqnt overcrowding and drunknness in these fetid dens, children are got rid of—‘sided,’ the slang is—by neglect and overlaying [...] 15,000 [babies] dying, or being ‘sided,’ they say at Liverpool, by cold, starvation, and ill-usage.