•sandstone • capstone • hearthstone
•headstone • gemstone • whetstone
•hailstone • gravestone
•greenstone • Wheatstone
•Tinseltown • ringtone • pitchstone
•millstone • whinstone • siltstone
•holystone • semitone
•stepping stone • coping stone
•baritone • acetone • dulcitone
•tritone • drystone • milestone
•cobblestone • gallstone • brownstone
•lodestone • soapstone • duotone
•microtone • bluestone • tombstone
•moonstone • touchstone
•sunstone • ironstone • undertone
•monotone • cornerstone
•Silverstone • overtone
•birthstone • flavone • endzone
•cortisone • ozone
a stone that forms the base of a corner of a building, joining two walls. ∎ a stone ceremonially laid usually at the corner of a foundation to mark the occasion of a building being erected.
an important quality or feature on which a particular thing depends or is based.
a stone that forms the base of a corner of a building, joining two walls; an important quality or feature on which a particular thing depends or is based (often in biblical allusions, as in Isaiah 28:16).