In a prohibitive manner; with prohibition; so as to prohibit: as, prices were prohibitively high.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
ad. to a prohibitive degree
Word Usage
"But even when I was a struggling Waldenbooks employee making $18,000 a year in prohibitively-expensive Connecticut, every six months or so I set aside a goodly amount on my credit cards to luxuriate."