(medicine) A calculus in the kidney.

(alchemy, uncountable) A supposed substance able to turn base metals, such as lead or mercury, into gold or silver, also sometimes claimed to cure any illness (as panacea) or confer immortality (as elixir of life), among other functions.

A stone set into the upper wall of Blarney Castle in Ireland, which if kissed is supposed to bestow the gift of the gab or blarney.

(idiomatic) A person who moves around a lot and never settles down; a vagrant. / (slang) A womanizer.

(idiomatic) Permanent; certain; firm.

To render something permanent, certain, or firm.

(archaeology, paleontology) A broad prehistoric period during which humans widely used stone for toolmaking. / (figuratively, informal) Any extremely primitive or undeveloped era.

A stone that can be stepped on in crossing something, especially a marsh or creek. / (idiomatic) Something used as a way to progress to something or somewhere else.

Alternative form of stepping stone

Alternative form of philosopher's stone.