Rocking-stone

Rock'ing-stone` noun A stone, often of great size and weight, resting upon another stone, and so exactly poised that it can be rocked, or slightly moved, with but little force.
Found on http://www.encyclo.co.uk/webster/R/88

Rocking-stone

• (n.) A stone, often of great size and weight, resting upon another stone, and so exactly poised that it can be rocked, or slightly moved, with but little force.
Found on http://thinkexist.com/dictionary/meaning/rocking-stone/
No exact match found