A grade assigned to a debt obligation by a rating agency to indicate a very strong capacity to pay interest and repay principal. Such a rating indicates only slightly lower quality than the top rating of AAA. Also called Aa.
aa (ä'ä) Pronunciation Key
A type of lava having a rough, jagged surface. It is relatively slow moving in its molten state, advancing in the form of massive blocks with fissured and angular surfaces that ride on a viscous interior. The blocks range in size between the size of a football and the size of a house. See Note at pahoehoe.
[ah-ah] 
ɑ