What is bliffil?

Some articles on bliffil:

My Bonny Light Horseman - Plot Introduction
... her crew but after an intense confrontation with Bliffil (an old nemesis of Jacky's) and British soldiers, Jacky surrenders, asking that the British spare her crew ... girl that was wrongly labeled a rogue by King George, despite Bliffil's accusation of her being known as "Tuppence a lay" on the HMS Dolphin and a threat to every man board ... Bliffil nags at Jacky, bullying her until the crew can't take it anymore ...
Bloody Jack (novel) - Plot Summary
... a sailor aboard the ship called Midshipman Bliffil starts to beat Jacky up, and only stops when the teacher yells at him ... She convinces Midshipman Jenkins to stand up to Bliffil and teaches him some fighting moves ... When Bliffil attacks Jacky again, Jenkins stands up to him ...