An adjective from biology: describing a living thing that carries a gene moved into it from a different kind of living thing. A tomato given a gene from a fish, a mouse carrying a piece of human DNA so that scientists can study a disease, rice given a gene that makes it produce vitamin A — all transgenic. The key idea is 'across a species line': the gene did not come from a relative you could have bred with normally, it was carried over from somewhere else. It is a technical word — you meet it in science classes, research papers, food-safety rules, and news stories about farming — and it is not used loosely in daily talk. In everyday conversation people say 'GM' or 'genetically modified' instead, and those two are wider: any lab change to the genes counts as GM, even just switching a gene off, while 'transgenic' specifically means a gene was brought IN from another species. So every transgenic organism is GM, but not every GM organism is transgenic. Journalists mix them up constantly, which is worth knowing when you read.