The term "lawn dart" is applied to a rocket that has returned to earth after a failure of the recovery system. It describes a rocket which has embedded itself in the ground, nose first.
A lawn dart is similar to a core sample except the nose cone remains in place prior to impact. Named after a lawn game of the 1960s in which large darts were thrown into the air to land inside rings placed on the ground about 25' apart (as in horse shoes).