I would assume a "second wave" means that it has crested in the same place twice. as opposed to calling Wuhan the first wave, Iran the second, Italy the third,

I would assume a "second wave" means that it has crested in the same place twice. as opposed to calling Wuhan the first wave, Iran the second, Italy the third, Spain the fourth, NYC the fifth, and so on. If NYC is bad again I'd call that a second wave. Florida is 1500 miles away and is experiencing their first wave, some time after NYC had theirs. The optimist in me has noticed that no locality experiencing a bad first wave has had a second wave yet. Perhaps that is a sign of herd immunity (helped by T-cells, if so). Time will tell...