'Highfalutin'' (also 'high faluting') has the meaning of 'pretentious' or 'pompous' - and can be used as an adjective for people or ideas, theories etc.

It's documented as having been in use in the mid 1800s.

Although its origin is not certain, etymologists suggest that it may have roots in 'high flying' or possibly 'high fluting' (i.e playing very high notes). Or possibly from 'flaunting'.

More ideas by Anatoly Liberman on the Oxford University Press blog

There's also a lively discussion of the word at Word-detective.com