OK found it: you can create key bindings to "macros": http://manpages.ubuntu.com/manpages/trusty/en/man3/readline.3readline.html
First, choose a key combination you want to use for this "kill whole word" operation -- peruse bind -sp | sort | less
to see what's in use.
Suppose Ctrl-xCtrl-w is OK, then
echo '"\C-x\C-w": "\ed\e\C-h"' >> ~/.inputrc
Start a new shell, and you should be good to go.
Although Ctrl-xCtrl-w is just as easy/awkward as Alt-dAlt-Backspace