Nisus

noun

1. An effort or endeavor to realize an aim.
2. The generative impulse occurring periodically, as with many creatures in the spring.
3. Effort; endeavor; conatus.
4. A genus of small hawks of the family Falconidæ, containing such as are called in Great Britain sparrow-hawks. See Accipiter.
5. A striving; an effort; a conatus.