needful

He became irritable, distressed, and anxious—struggled hard to get the needful sum together, struggled and strove; but failed.

It is needful to have the time fixed, and the law therefore has established a reasonable time.

There are many cases like this in which one's common sense fails to furnish a correct, yet needful guide.

The period of infancy is fixed by law, and is therefore a conventional, yet needful regulation.

Rise early enough to have ample time for arranging everything needful for the day's journey.