a. Instant; unprepared; ready; extemporaneous; unrehearsed; as, an offhand speech; offhand excuses; an offhand comment. -- adv. In an offhand manner; as, he replied offhand. [ 1913 Webster ]
adj. 1. same as offhand and off-the-cuff. Syn. -- ad-lib, extemporaneous, extemporary, extempore, offhand, off-the-cuff, unpremeditated, unrehearsed. [ WordNet 1.5 ]
2. Without, or seeming to be without, plan or method; casual. Syn. -- casual, offhand. [ WordNet 1.5 ]