[Advaita-l] Definition of VASANAS ?

[Mahadevan Iyer]

What is the correct definition of VASANAS ?
is it :-
1. Inhibition.
2. Behavioural Tendency.
3. Karmic imprint.
4. Unmanifested desire.
5. Habitual egoic desires.
6. Impressions.
7. Desire in subtle form.

The illusory Samsaric Vasanas that have arisen through the practice of many
hundreds of lives never perish except through the practice of Yoga for a
long time.

How did the Vasana start appearing ?

Is there a cause-effect explanation for HOW or WHY the Non-Dual appears as
Dual ?

*Regards,*
Mahadevan Iyer