Is there some global method to reduce the importance of certain words?

Is there a way to provide a weighting or boost value per word at the index
or mapping level?

I can probably accomplish this at the query level, but that could be very
bad if I have 50 words whose impact I need to reduce.

I feel like this would be a token filter, but I can't seem to find anything
matching. It'd be great to be able to establish a config file with a list
of words and their boost values.

I also posted this question on stackoverflow here in
case you need some rep!