(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.

(UK, Australia, colloquial) Generalized expression of surprise or amazement, or just for emphasis.

Belonging in the Stone Age.

Any of several species of large terrestrial birds in the family Burhinidae.

oxylith