Definition of ultimatum :
A final proposition, concession, or condition; especially, the final propositions, conditions, or terms, offered by either of the parties in a diplomatic negotiation; the most favorable terms a negotiator can offer, the rejection of which usually puts an end to the hesitation.
- A week or more ago Austria Hungary sent an ultimatum to the Serbian government, to which an unsatisfactory reply was received. - "The Secret Witness", George Gibbs.
- One was an appeal to his troops to prevent desertion among the country folk who felt it imperative to get in their crops; the other was an ultimatum to Hull summoning him to surrender. - "The Niagara River", Archer Butler Hulbert.
- My financial agent wires me that the Press will announce to- morrow that Austria has presented an ultimatum to Servia demanding an answer within forty- eight hours. - "The Major", Ralph Connor.