Basis (6)
'basis' is the definition.
(synonyms)
This is all the clue.
(Other definitions for foundation that I've seen before include "Base" , "Groundwork, basis" , "Underlying basis" , "Artificial jet of water" , "cosmetic aid?" .)
'basis' is the definition.
(thesaurus)
This is all the clue.
(Other definitions for bottom that I've seen before include "Lowest point - weaver" , "seat" , "Shakespearean - rear" , "one of Shakespeare's comic characters" , "Rump" .)
'basis' is the definition.
(synonyms)
This is all the clue.
(Other definitions for cornerstone that I've seen before include "Something of prime importance" , "Key figure" , "Mainstay" , "Supporter" .)