When we were growing up
there was a derogatory term.

To be referred to as a Tull,
had a negative connotation.

Tull, Jethro |tʌl|
(1674–1741), English agriculturalist. In 1701 he invented the seed drill, a machine which could sow seeds in accurately spaced rows at a controlled rate, reducing the need for farm labourers.

Jethro Tull, the rock group were
called after this man. As yet, I
have not ascertained, what growing
wheat for bread has to do with being
a nasty piece of work, I.E. a Tull?