the GNU version of the Collaborative International Dictionary of English
n. An old cat, especially a she-cat.
n. A bad-tempered old woman.
The Century Dictionary and Cyclopedia
n. A cat, especially an old cat: often used as a proper name, with or without a capital letter.
Word Usage
"A grimalkin, that is to say, a Cat, went out one night to a certain garden, in search of what she might devour, but found nothing and became weak for the excess of cold and rain that prevailed that night."