n.
     - an official authorization enabling the police or some other body to make an arrest, search premises, etc.
 - a document entitling the holder to receive goods, money, or services.
 - Finance  a negotiable security allowing the holder to buy shares at a specified price at or before some future date.
 - justification or authority.
 - an official certificate of appointment issued to an officer of lower rank than a commissioned officer.
 
v.
  - justify or necessitate.
 - officially affirm or guarantee.
 
 
  Phrase
  
    
      - I 
(or I'll)
 warrant (you)
 dated no doubt. 
    
   
  Derivative
  
    - warrantable adj.
  - warrantableness n.
  - warrantably adv.
  - warranter n.
 
   
  Etymology
  ME (in the senses ‘protector, safeguard’, and ‘protect from danger’): from vars of OFr. guarant (n.), guarantir (v.), of Gmc origin; cf. guarantee.