The word is proceeded .
Sure, you can report the member - go to Help & Support at the bottom of the page, then Contact Support - there's an option to report abuse on the next screen.
There's no surefire way to block every one of these sorts of people from the site before they manage to spew an insult or two, however. If this sort of meaningless crap (which, incidentally, shows you completely shot his chess confidence with your play) bothers you, however, the best thing to do is to disable chat completely.
I was playing LiveChess several days ago, and I played a player lower rated than I was. I won rather handily; he then proceeded to challenge me to a rematch, and I accepted. He then proceeded to call me a "cu nt" and said my mother should be "ra ped;" he then allowed the game to abort. I responded by analyzing the game, posting the analysis on my blog and posting a note to inform him of this; he then posted the note "your blocked cu nt." Is there a process for reporting members like this? I don't want to deal with this problem in the future.