Verb (5-dan, す, transitive)
1. to miss; to overlook; to fail to notice
一瞬の変化も見逃さない。I won't miss even a momentary change.
2. to let pass (a matter); to overlook (e.g. a wrongdoing); to turn a blind eye to
気付いていながら、それを見逃しているということになる。It means that you are overlooking it despite being aware of it.
3. to pass up (e.g. an opportunity)
これを見逃す手はない。There's no reason to pass this up.
4. to let (a good ball) go by