adj. indispensable, essential
The pilot had hung out his lights an indispensable precaution to take in these very busy waters.
fearful that the war might cut off forever the dynasty of the Lacours, indispensable to the welfare of the State, had had his son mustered into the auxiliary service of the army. By this arrangement Lacour, his heir
He and his gang, who believed that at seven a full dress or Tuxedo was indispensable, were like a band of Indians, bringing to Paris the wild customs of the plains.
The Herr Professors had proved to their countrymen that such sacking incursions were indispensable to the highest civilization,
The women who in Paris might be counted by the dozens appeared here in hundreds. The scandalous drunkenness here never came by chance, but always by design as an indispensable part of the gaiety.
was still but a possibility. She herself had prepared the soldier's outfit so that the small valise might contain all that was indispensable for campaign life.
For others, this hobby can become something uncontrollable and indispensable in their lives.
Arms control, disarmament and non-proliferation continue to be a central, indispensable element in cooperation among States.
But Britain’s military contribution to the war effort was not indispensable, so Bush did not have to heed Blair’s advice.