Definition of "drastic"

Seeing the British establishment struggle with the financial sector is like watching an alcoholic who still resists the idea that something drastic needs to happen for him to turn his life around.

2013 June 28, Joris Luyendijk, “Our banks are out of control”, in The Guardian Weekly, volume 189, number 3, page 21

Great statesmen err, and why not small medical men? Mr. Wrench did not neglect sending the usual white parcels, which this time had black and drastic contents. Their effect was not alleviating to poor Fred [...]

1871-72, George Eliot, Middlemarch