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.
All the answers regarding old English usage are correct. However the key here is in the use in a song by The Business who were/are a key pillar of the 80s Skinhead Oi music movement. The term Herbert was used to describe those who were not punks or skinheads.