Large clock hands are those that are longer than around seven inches (talking the minute hand, not the hr hand). The reason huge clock hands are so marked is that sizes higher than that cutoff length consider way too much for a common motor to rotate. In other words, the standard torque wants, requiring the developer of the wrist watch to order a high-torque motion instead.
Big clock hands are in theory unrestricted in length, however virtually speaking you won't see any kind of longer than eighteen inches, indicating that the corresponding clock would be at the very least a lawn in size. Also after that, the likeliest application for such a watch would be something placed straight to the wall surface (using the wall as the dial, so to speak) without being confined in a case.