the GNU version of the Collaborative International Dictionary of English
ad. Without design; accidentally; fortuitously; by chance; occasionally.
The Century Dictionary and Cyclopedia
In a casual manner; accidentally; fortuitously; without design; by chance: as, to meet a person casually; to remark casually.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
ad. in an unconcerned manner
ad. not methodically or according to plan
Word Usage
"He also knew a great deal about history, which he used in his "Time Patrol" stories—the one here has a title casually truncated from Cato, "Delenda Est" the missing Latin word is "Carthago"."