Spyhopping is when orcas raise their heads above water to see what's going on around them - particularly useful when hunting.

Let H be a traversal of an undirected graph G = (X, U). For given H, the set U can be split into set of tree edges from the forest G_H and the set of inverse edges that do not belong to this forest.

Xerxes strange Lydian love, the Platane tree, / Was lov'd for age, none being so large as shee ….

Servius the Grammarian being troubled with the gowt, found no better meanes to be rid of it, than to apply poison to mortifie [translating tuer] his legs.