वासना, vāsanā

desire, inclination,
from the root वास्, vās — "dwelling, residue, remainder"

Strength of habit, tendency to certain behavior. The term in Hinduism and Buddhism, which means the action of potential factors in the mechanism of karma and samsara.

Vasana usually refers to trends emanating from past lives, and most of this kind of unconscious impressions is hidden in the psychics, as if in a dormant state. Only those are manifested that can find a place in this life. 

Vasanas form our relationship to the world and motivation and are the result of sanskaras.