E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
A giant who keeps a bridge leading to a castle by a riverside, in which a beautiful lady is besieged. Sir Lybius, one of Arthurs knights, does battle with the giant; the contest lasts a whole summers day, but terminates with the death of the giant and liberation of the lady. (Libeaux, a romance.)