1. (

• basis ,
• base ,
• foundation ,
• fundament ,
• groundwork ,
• cornerstone

) the fundamental assumptions from which something is begun or developed or calculated or explained; "the whole argument rested on a basis of conjecture" ;

2. (

• foundation ,
• base ,
• fundament ,
• foot ,
• groundwork ,
• substructure ,
• understructure

) lowest support of a structure; "it was built on a base of solid rock"; "he stood at the foot of the tower" ;

3. (

• groundwork

) preliminary preparation as a basis or foundation; "we are prepared today because of groundwork that was done ten years ago" ;