From Longman Dictionary of Contemporary Englishpitonpi‧ton /ˈpiːtɒn $ -tɑːn/ noun [countable] DSODLOa piece of metal used in rock climbing that you attach onto a rock to hold the rope → crampon
Examples from the Corpus
piton• Now, somehow holding a piton with his useless hand, he had to hammer it into the rock with the other.• With cords and pitons they anchored him to the rock.• The secret weapon of the ascensionists, unlocking the door to Bosigran's hardest faces, were the hammer and piton.• Respect established climbing traditions in ethical matters such as the use of chalk, pitons, bolts etc.• But he was on a straight rock surface that required pitons, which he did not have.• These may be quick direct belays on situ pitons or round spikes or flakes.Origin piton (1800-1900) French 