gensym /jen'sim/ [from MacLISP for `generated symbol'] 1. v. To invent a new name for something temporary, in such a way that the name is almost certainly not in conflict with one already in use. 2. n. The resulting name. The canonical form of a gensym is `Gnnnn' where nnnn represents a number; any LISP hacker would recognize G0093 (for example) as a gensym. 3. A freshly generated data structure with a gensymmed name. Gensymmed names are useful for storing or uniquely identifying crufties (see cruft).