the GNU version of the Collaborative International Dictionary of English
ad. In a functional manner; as regards normal or appropriate activity.
The Century Dictionary and Cyclopedia
In a functional manner; by means of functions; specifically, in zoöl., with reference to function alone: as, the maxillæ of crustaceans are morphologically limbs, but functionally jaws.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
ad. with respect to function
Word Usage
""It's what they call functionally obsolete, meaning it's narrow and the trusses have low clearance," Elkins said."