The name given to a bhikkhuní, who, so Ananda tells Udáyí, came to see him at the Añjanavana in Sáketá. The nun asked him for what purpose the Buddha requested that samádhi should be practised and Ananda answered that it was for the purpose of obtaining insight (A.iv.427f).
The Commentary (AA.ii.812) says that the bhikkhuní was so called because she came from a city called Jatilagaha.