- aa - a dry form of lava resembling clinkers
--1 is a kind of lava
- Alcoholics Anonymous, AA - an international organization that provides a support group for persons trying to overcome alcoholism
--2 is a kind of nongovernmental organization, NGO
- Associate in Arts, AA - an associate degree in arts
--3 is a kind of associate degree, associate
- Alcoholics Anonymous, AA - an international organization that provides a support group for persons trying to overcome alcoholism