Denshi Jisho — Online Japanese dictionary

そせき foundation stone; cornerstone
Common word, Noun 
そざい foundation materials
Noun 
いしずえ foundation stone; cornerstone
Common word, Noun 
を築く いしずえをきずく to lay the foundation (for)
Expression, Godan verb with ku ending 

You can also

Look up kanji details for 礎.

Try a Yahoo Jisho search for 礎 .
Try a Goo Jisho search for 礎 .
Try a Google search for 礎 .