have the goods on someone Definition

1. Articles for sale; merchandise.

Thesaurus: commodities, merchandise, wares, stock, vendibles.
2. Freight. Often as adj.

Example: goods train
Thesaurus: property, effects, possessions, belongings, equipment, baggage, furnishings, furniture, appurtenances, chattels, traps.
3. colloq
The required result.
Example: deliver the goods
4. old use
Personal possessions.

colloq
To have proof of wrongdoings or crimes committed by them.