Nouns

(n)footing, basis, grounda relation that provides the foundation for something“they were on a friendly footing”, “he worked on an interim basis”
(n)basis, base, foundation, fundament, groundwork, cornerstonethe fundamental assumptions from which something is begun or developed or calculated or explained“the whole argument rested on a basis of conjecture”
(n)basis, basethe most important or necessary part of something“the basis of this drink is orange juice”