See the entire entry for btrh@mn prep. behind

TN Ex11:5marg :בכורא דפרעה דהוה עתיד \למיתב על כורסי /למתעב כל כורסייה : Pharaoh's first born who was destined to sit on the throne (var.: to defile all thrones)

See the entire entry for tˁb vb. to be abhorrent