aegis: (under the aegis of: under the sponsor of)

His green card is issued under the aegis of his company.

aesthetic: (beautiful, art)

She decorated her house aesthetically with beautiful paintings and handcrafts.

affable: (diffusing warmth and friendliness)

The hostess's gracious look and affable personality make the visit to the exhibition so much more enjoyable. 

aggravate: (make worse)

Two of them don't get along already. You should not add fuel on the fire to aggravate their relationship.

agnostic: (uncertainty of God existence)

She is an agnostic because she doesn't know if God really exists without any objective proving. 

agonize: (suffer extreme pain or great anguish)

She agonized over the decision to have a mastectomy instead of taking chemotherapy to treat her breast cancer.

alacrity: (liveliness and eagerness)

The child responded with alacrity when the doctor asked him if he wants to go home after staying in the hospital for 2 weeks.