Thom·son (t?m?s?n), James 1700-1748. Scottish-born British poet whose works, most notably The Seasons (1726-1730) and The Castle of Indolence (1748), presaged romanticism.American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.