vigg.

From Old Swedish vigge (“wedge”), from Old East Norse *viggʀ (compare Old West Norse veggr), from Proto-Germanic *wagjaz. Cognate of English wedge. The thunderbolt sense stems from Medieval and Viking Age folklore; when peasants found Stone Age axe heads (i.e. stone wedges) in the ground, it was thought that these had been sent down with the lightning strikes of the god Thor (whom hunted giants above the clouds and created thunder when he struck them), thus named åskviggar (“thunder wedges”) or torsviggar (“thor wedges”). They were thought to protect from lightning strikes, since “lightning never strikes the same spot twice”, and thus were popularly put into house foundations. Name of the bird due to the long tuft of hair at the back of the neck of males.

Clipping of vigilans. See vigga.