What does "clear of clouds" mean in FAA FAR part 103?
It means you have to stay outside the cloud while flying. You're expected to use your own good judgment (remember it is illegal to fly into the cloud, and if you don't have proper instruments and know what you're doing, it's downright deadly) but there is no minimum clearance as there is at other times, so if you really felt like a daredevil you could reach out and touch a low-hanging "popcorn cloud" with your wingtip. This term is often used in situations where vertical separation minima from clouds is not practical (to stay 500 feet underneath a VMC-friendly cloud layer would require altitudes as low as 500 feet AGL; there are a lot of hazards to navigation at that height from radio antennae to city skylines)