An ajah was originally defined as "an informal and temporary group of people gathered together for a common purpose or goal, or by a common set of beliefs."
"She is dangerous, Great Mistress. Her talent could reveal what should not be revealed."
Crystalline laughter answered her. "Such as? You? Your Black Ajah sisters? Or perhaps you think to safeguard me? You are good sometimes, child." That silvery voice was amused. Alviarin felt her face heat and hoped that Mesaana read the shame, not the anger. "Do you suggest that our Elaida should be disposed of, child? Not yet, I think. She has her uses still. At least until young al'Thor reaches us, and very likely after. Write out her orders and see to them. Watching her play her little games is certainly amusing...
... You children almost match the ajah at times...
... Will she succeed in having the King of Illian and the Queen of Saldaea kidnapped? You Aes Sedai used to do that, didn't you, but not for - what? - two thousand years? Who will she try to put on the throne of Cairhien? Will the offer of being king in Tear overcome the High Lord Darlin's dislike of Aes Sedai? Will our Elaida shoke on her own frustration first? A pity she resists the idea of a larger army. I'd have thought her ambitions would leap at that."