However,tumshie is not a word from a regional variation of English as stated in a previous entry, though the definition, as far as it goes (see below), is correct.
Rather than coming from a regional variation of English, tumshie is a Lowland Scots (also known as Lallans) word. It is not just a petty nationalistic distinction- though I will admit to a bit of that too. Both modern English in its various guises and Lowland Scots evolved out of an earlier language sometimes called Middle English. Just as both humans and chimps evolved from a common ancestor but are not the same species both Scots and English share a common ancestor but despite what our teachers were told to tell us Scots is not a vulgar form of English but a language in its own right, with differences in some grammar and syntax as well as vocabulary. It is the language Robert Burns wrote in which is why most people who speak English need half his words translated!
The most common use of the word tumshie in modern Scotland is not the turnip definition, but one derived from it. To call somebody a tumshie is a derogatory but not too harsh way of calling them a gullible or foolish person. It comes from the expression "tumshie-heid" meaning "turnip-head".