1. artless - Ingenuous.
2. ascendant - Dominant.
3. ascension - The act of rising.
4. ascent - A rising, soaring, or climbing.
5. ascetic - Given to severe self-denial and practicing excessive abstinence and devotion.
6. ascribe - To assign as a quality or attribute.
7. asexual - Having no distinct sexual organs.
8. ashen - Pale.
9. askance - With a side or indirect glance or meaning.
10. asperity - Harshness or roughness of temper.
11. aspirant - One who seeks earnestly, as for advancement, honors, place.
12. aspiration - An earnest wish for that which is above ones present reach.
13. aspire - To have an earnest desire, wish, or longing, as for something high and good, not yet attained.
14. assailant - One who attacks.
15. assassin - One who kills, or tries to kill, treacherously or secretly.