In an impassive manner; without sensibility to pain or suffering; without sign of feeling or sensibility.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
ad. in an impassive manner
Word Usage
""I don't know anything," impassively; "unless it is that I wouldn't be in your shoes if I got a dollar for every cent you've made out of this cursed business.""