1. Proof of stake (consensus mechanism for blockchain validation based on quantity of holdings)

1. Point of sale
    
2. [vulgar] Piece of shit
    
3. [informal] Parent over shoulder

1. A noncommissioned officer in the Navy or Coast Guard with a rank comparable to sergeant in the Army
   "The PO supervised the maintenance crew";
   - petty officer, P.O.
    
2. An independent agency of the federal government responsible for mail delivery (and sometimes telecommunications) between individuals and businesses in the United States
   - United States Post Office, US Post Office, Post Office
    
3. A commercial document used to request someone to supply something in return for payment and providing specifications and quantities
   - order, purchase order

Type of: commercial document, commercial instrument, enlisted officer, independent agency, noncom [informal], noncommissioned officer

Encyclopedia: PoS