devil's own adjective2 •Particularly devilish; highly unpleasant or evil.The reason why our distressed young teacher found it the devil's own job to get the students to write was probably basically that they were not led to believe that written work was expected of them. — 1973 •Intense.'The Capt'n's been ridin' the devil's own pace,' said Dalton the coachman. — 1859