[1] : The Collaborative International Dictionary of English v.0.48

grimalkin \grimal"kin\, n. for graymalkin; gray + malkin.
   1. an old cat, especially a she-cat. --j. philips.
      1913 webster

   2. a bad-tempered old woman.
      pjc

[2] : Moby Thesaurus II by Grady Ward, 1.0

43 moby thesaurus words for "grimalkin":
   cheshire cat, chinchilla cat, jezebel, maltese cat, alley cat,
   beldam, bitch-kitty, blue cat, calico cat, cat, feline, fury, gib,
   gib-cat, hag, hellcat, hellhag, house cat, kit, kitling, kitten,
   kitty, kitty-cat, mouser, puss, pussy, pussycat, she-devil,
   she-wolf, silver cat, siren, tabby, tabby cat, termagant,
   tiger cat, tigress, tom, tomcat, tortoise-shell cat, virago, vixen,
   wildcat, witch

Grimalkin >> G Words
Grimalkin, definition of term: Grimalkin
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