the GNU version of the Collaborative International Dictionary of English
adj. Of moment or consequence; very important; weighty
The Century Dictionary and Cyclopedia
Of moment or consequence; of surpassing importance; critical.
Synonyms Grave, serious.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
adj. of very great significance
Word Usage
"The Australian prime minister also noted what she called the "momentous" upheaval in the Middle East, and pledged her alliance with the United States in condemning Iran's nuclear program, and in a call for an Israeli-Palestinian resolution."