CORNERSTONE
cornerstone
(noun) a stone at the outer corner of two intersecting masonry walls
cornerstone
(noun) a stone in the exterior of a large and important building; usually carved with a date and laid with appropriate ceremonies
basis, base, foundation, fundament, groundwork, cornerstone
(noun) the fundamental assumptions from which something is begun or developed or calculated or explained; “the whole argument rested on a basis of conjecture”
Source: WordNet® 3.1
Etymology
Noun
cornerstone (plural cornerstones)
A stone forming the base at the corner of a building.
Such a stone used ceremonially, often inscribed with the architect's and owner's names, dates and other details.
(figuratively) That which is prominent, fundamental, noteworthy, or central.
Coordinate terms
• foundation stone
• keystone
• milestone
• quoin
• touchstone
Anagrams
• nonsecretor
Source: Wiktionary