Also found in: Legal.
Very shocked or distraught. I was beside myself when I found out I'd been rejected from my first-choice school. Honestly, we've all been beside ourselves since the funeral.
beside oneself (with something)
Fig. in an extreme state of some emotion. I was beside myself with joy. Sarah could not speak. She was beside herself with anger.
In a state of extreme agitation or excitement, as in She was beside herself when she found she'd lost her ring, or Peter was beside himself with joy-he'd won the poetry award. This phrase appears in the New Testament (Acts 26:24): "Paul, thou art beside thyself; much learning makes thee mad." [Late 1400s]