adv. [ 1913 Webster ]

1. At which; upon which; whereupon; -- used relatively. [ 1913 Webster ]

They vote; whereat his speech he thus renews. Milton. [ 1913 Webster ]

Whereat he was no less angry and ashamed than desirous to obey Zelmane. Sir P. Sidney. [ 1913 Webster ]

2. At what; -- used interrogatively; as, whereat are you offended? [ 1913 Webster ]