Answer:

cornerstone

Answer	Crossword Clue
CORNERSTONE	Foundation
CORNERSTONE	Part of a foundation.
CORNERSTONE	Basic element

CORNERSTONE	Building block
CORNERSTONE	Place for a date, frequently
CORNERSTONE	Place to find a date
CORNERSTONE	Place to look for a date

Crossword

a puzzle consisting of a grid of squares and blanks into which words crossing vertically and horizontally are written according to clues.