Definition of "overmaster"

overmaster

verb
third-person singular simple present overmasters, present participle overmastering, simple past and past participle overmastered
1. (transitive) To overpower or overwhelm.
  Quotations
  Sir Jasper started from his chair, ashamed of the sick fancies that had, for the moment, overmastered him.
  1837, L[etitia] E[lizabeth] L[andon], “An Evening Alone”, in Ethel Churchill: Or, The Two Brides. […], volume I, London: Henry Colburn, […], page 303
  Did I forget! Shall I ever . . can I ever! Can any of us ever forget that terrible scene! Mina struggled hard to keep her brave countenance, but the pain overmastered her and she put her hands before her face, and shuddered whilst she moaned.
  1897, Bram Stoker, chapter 21, in Dracula, New York, N.Y.: Modern Library