Mary Shelley ma·rys·hel·ley uncommon noun 1. English writer who created Frankenstein''s monster and married Percy Bysshe Shelley (1797-1851) SynonymsShelleyMary ShelleyMary Wollstonecraft ShelleyMary Godwin Wollstonecraft Shelley Related words Broader terms writer WordNet 2.1 (Princeton University). WordNet 2.1 Copyright Princeton University. All rights reserved.