beside oneself, almost out of one's senses from a strong emotion, as from joy, delight, anger, fear, or grief:
He was beside himself with rage when the train left without him.
Origin
before 1000;Middle English; earlier bi-siden,Old Englishbī sīdan, be sīdan; see be-, side
Can be confused
beside, besides (see usage note at the current entry)
Usage note
For the prepositional meanings “over and above, in addition to” and “except” besides is preferred, especially in edited writing: Besides these honors he received a sum of money. We heard no other sound besides the breaking surf. However, beside sometimes occurs with these meanings as well.
Examples from the web for beside
For a certain kind of company, recessions may be beside the point.
Located beside the lake for which the city is named, the campus is spectacular and visitors marvel at its beauty.
But the quality of the service is so poor that a parallel private service is growing up beside it.
Sha sits beside me on a folding chair, enjoying an early morning cigarette after a bath in the river.
On the terrace, a few parents chatted beside an alluring spread of bagels, coffee and fruit.
Set the container in a high-visibility area, such as on a patio or beside an entry.
Nearby, in a storage room beside the vault, an ordinary-looking red fire extinguisher was strapped to the wall.
Barns lean wildly or collapse inwards, slouchy silhouettes beside neat rows of corn.
To support himself, he worked as a laborer in a limestone quarry and later a factory, reading books on theology beside a boiler.
The miller is at home near his millstones and beside his dam.
British Dictionary definitions for beside
beside
/bɪˈsaɪd/
preposition
1.
next to; at, by, or to the side of
2.
as compared with
3.
away from; wide of: beside the point
4.
(archaic) besides
5.
beside oneself, (postpositive) often foll by with. overwhelmed; overwrought: beside oneself with grief
adverb
6.
at, by, to, or along the side of something or someone
Word Origin
Old English be sīdan; see by, side
Word Origin and History for beside
prep.
Old English be sidan "by the side of" (only as two words), from be- + sidan dative of side (n.). By 1200, formed as one word and used as both adverb and preposition. The alternative Middle English meaning "outside" led to the sense preserved in beside oneself "out of one's wits" (late 15c.).