Ul`ti*ma"tum (?), n.; pl. E. Ultimatums (#), L. Ultimata (#). [NL. See Ultimate.]
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 final demand, the rejection of which may lead to a resort to force or other compelling action by the party presenting the ultimatum. -->
© Webster 1913.