Binding Fn-Delete in zsh on Mac OS X
Solution 1:
First figure out what sequence it generates.
echo "CtrlVFnDelete" | od -c
Then bind that sequence using the normal zsh bind mechanism.
Solution 2:
For me the above didn't do the trick so I added the following key binding to my ~/.zshrc:
bindkey "\e[3~" delete-char
FYI: I am on a Mac (High Sierra).