I wasn't sure after seeing this at dictionary.com:
Related Words for : sue
action, litigate, process
Related Words for : action
litigate, process, sue, accomplish, carry out
...with "litigate and process" common to both.
And then, I've seen clues where verbs are "made up";
like "I'll action you" instead of "I'll take action against you"...
A true friend steps in when the rest of the world steps out.