Atomic meaning : An atomic operation. Of or relating to atoms; composed of atoms; monatomic. Employing or relating to nuclear energy or processes. Infinitesimally small. Unable to be split or made any smaller. Of an operation: guaranteed to complete either fully or not at all while waiting in a pause, and running synchronously when called by multiple asynchronous threads. (of a commit in a VCS) Containing a single change, as opposed to involving numerous unrelated changes.