On Terminal by default,
option-backspace does not delete the previous word. To have text-editing in the terminal behave similarly to other text editing in Mac OS, open Terminal Settings > Profiles. Click on the "Basic Default" profile on the sidebar, then click on the "Keyboard" tab. Enable "Use Option as Meta key".
Test that this works by opening a new Terminal window, typing a word, then pressing
option-backspace to delete it.