When to use 'no good'; when to use 'not good'? [duplicate]
Solution 1:
From OED (good):
colloq. to be any, some, no good: to be any, some, no use. Also of persons, to be no good = 'to be a bad lot', to be worthless. Also of things a bit of no good, quite a lot of harm.
No good functions as both an attributive adjective (e.g., a no-good dirty dog) and noun (e.g., what a no good)
On the other hand, saying that something is not good is just indicating that the adjective 'good' does not apply to it. In many instances, no good and not good can both be used. No good is certainly the more informal alternative.