Abhinivesa

Abhinivesa (Sanskrit) [from abhi towards + ni down + the verbal root vis to enter] To enter into completely; application, intentness, devotion, tenacity, determination to effect a purpose or attain an object. In the Bhagavad-Gita, when used with manas (mind) and atman (self) it means to devote one's attention to.
In the Sankhya and Yoga systems, abhinivesa or tenacity for life is the last of the five hindrances (klessa). W. Q. Judge defines it as "idle terror causing death" -- a permissible extension of meaning (WG 1).