Necessary; required. See Synonyms at indispensable.(adjective)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "needful" in a sentence
"It meant they were just sick of this constant idea that the one thing needful is to put more people in the West -- and more people, and yet more people."
"Methinks it must have been a precursive vapour of the madness that afterwards infolded me, for I know well that there is not one called Death, that he is but a word needful to the weakness of human thought and the poverty of human speech; that he is a no-being, and but a change from that which is."
"The one thing needful is certainly meant of that which Mary made her choice -- sitting at Christ's feet, to hear his word."