1 (uncountable) The property of being mentally ill; mental disorders taken as a whole.  2006, R. Keith Sawyer, Explaining Creativity: The Science of Human Innovation, Oxford University Press US, ISBN 9780195161649, page 87:
Essay on Gulliver's change throughout Gulliver's Travels - Gulliverâs change throughout Gulliverâs Travels Throughput the book âGulliverâs Travelsâ by Jonathan Swift, the character Gulliver changes many times. During and after part two and four of the book a noticeable change in Gulliver starts to occur.
As for Gulliver, in addition to being pretty flexible with class and language, Gulliver also has a head mechanically turned (1.6.19). He offers to turn this mechanical ability to the advantage of the King of Brobdingnag by making gunpowder, but is refused.