tail event

Noun

 * 1)  an event associated with a given infinite sequence $$Y=\{ y_k| k\ge k_0 \}$$ that is determined by any subsequence of the form $$Y_n=\{ y_k|k\ge n\}, n\ge k_0$$ (a "tail" of that sequence)
 * 2) a low-probability event
 * 3) an event that initiates an activity
 * 1) an event that initiates an activity
 * 1) an event that initiates an activity
 * 1) an event that initiates an activity