1) An archaic form of after or afterwards.
1586 he must pay xs at candyllmes and xs at after, Huddersfield
1674 he parted with his said Chapman at after which time they did not meete againe as he now confesseth, Grassington
1736 the pickpocket rode away with the horse that belonged to the said Driver and was never heard of at after, Wakefield
1758 shalloons to bee scowred with hogs dung and lant … and att after take them to the river and pos them weel with your feets, Wakefield. It remains in use.