Lapiths were a Greek people who lived in the north of Thessaly. They traced their origin back to Ixion or (more obviously) to Lapithes, an obscure son of Apollo and Stilbe. They became famous through their battle with the Centaurs.
They have been traditionally explained as 'pillagers', from lapazo, 'to plunder', 'carry off, but perhaps really they were 'stone-persuaders', from laas, 'stone' and peitho, 'to persuade', 'prevail', this being a poetic term for town builders.