The American Heritage® Dictionary of the English Language, 4th Edition
n. A woman who has made a legally valid will before death.
the GNU version of the Collaborative International Dictionary of English
n. A woman who makes and leaves a will at death; a female testator.
The Century Dictionary and Cyclopedia
n. A woman who makes a will or testament; a woman who has made a will or testament and dies leaving it in force.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
n. a female testator
Word Usage
"The frame was made, and the will hung up opposite to her bed, unknown to any one but Leonard; and, by dint of his repeated reading it over to her, she learnt all the words, except "testatrix," which she would always call "testy tricks.""