- Needed; necessary; mandatory; requisite; indispensible.
needful (plural needfuls)
Usage notes 
Commonly found in phrases such as "do the needful" or "please do the needful"; which occur commonly in Indian English but are held as archaic in other dialects; nonetheless being heard more and more by speakers of said dialects in their interactions with speakers of Indian English. This has to some extent lead to these phrases being seen as stereotypical of Indian English and used in a parodying context by speakers of other dialects, some of whom find their usage odd and/or pretentious.