I must confess I don't like the term "rationalism" as it has Vulcan-Hollywood-Rationalism connotations. In the past, this term was often used to describe attitudes that are highly impractical and ideological. More in PDF On the "Oakeshottian scale" LW-Rationalism is far closer to the pragmatic attitude Oakaeshott endorses than to that type of quasi-rationalism he criticizes.
If I had a time machine I would probably try to talk Eliezer into choosing another name. What name that would be I am not so sure, perhaps Pragmatism - after all Peirce is a big influence and his philosophy WAS called Pragmatism. (But hold on, the term Pragmatism is also used by Richard Dworkin and I am not sure I would like that association.)
Bygones are bygones, so now all I can do is to recommend you all to spread the ideas WITHOUT putting any kind of label on them. Just simply as good ideas, ideas that work. This makes sense even if you like the term "Rationalism". Because you probably see it is easier to get people to adopt ideas if we are not asking them to identify with any label.
I think if we just added a table for synonyms and have and a few more we would be good.
I told an intelligent, well-educated friend about Less Wrong, so she googled, and got "Less Wrong is an online community for people who want to apply the discovery of biases like the conjunction fallacy, the affect heuristic, and scope insensitivity in order to fix their own thinking." and gave up immediately because she'd never heard of the biases.
While hers might not be the best possible attitude, I can't see that we win anything by driving people away with obscure language.
Possible improved introduction: "Less Wrong is a community for people who would like to think more clearly in order to improve their own and other people's lives, and to make major disasters less likely."