to know one's onions
01
to have a great deal of information regarding a particular subject
![to [know] {one's} onions definition and meaning](https://cdn.langeek.co/photo/42194/original/?type=jpeg "to [know] {one's} onions definition and meaning")
Idiom
Informal
أمثلة
When it comes to repairing vintage cars, John really knows his onions; he can fix anything under the hood.
She's the one you should consult about gardening; she knows her onions when it comes to growing beautiful flowers.
