(Lat. for a thorn, or prickle, also backbone, whence spine), in architecture, the term given to the low podium wall which divided the circus of the Romans and round which the chariots ran; at each end of it was the meta or goal. On coins, gems and bas-reliefs it is shown with numerous other features on it, such as obelisks (of which those from the spina of the Circus Maximus are now in the piazzas of the Lateran and del Popolo), small aedicula or pairs of columns carrying an entablature, altars, statues, trophies, &c.