hidden oscillation
英[ˈhɪdn ˌɔsəˈleɪʃən]美[ˈhɪdn ˌɑsəˈleʃən]
An oscillation in a dynamical system can be easily localized numerically if initial conditions from its open neighborhood lead to long-time behavior that approaches the oscillation. Such oscillation (or a set of oscillations) is called an attractor, and its attracting set is called the basin of attraction.