Oscillation of a sequence (shown in blue) is the difference between the limit superior and limit inferior of the sequence. In mathematics, the oscillation of a function or a sequence is a number that quantifies how much a sequence or function varies between its extreme values as it approaches infinity or a point.
Herbert is a mild form of abuse meaning a silly, or dim-witted person. The origin of this term seems to be that it was derived from the name Herbert, which meant bright.. It was used in the very direct opposite, to mean dumb.
A highwayman is a thief who usually steals from travelers. The term is typically used in both fictional and non-fictional historical accounts. In fiction stories, he is usually a gentleman who has manners and uses non-violent threats to steal from travelers.