One of the mysteries of the English language finally explained.
Definition of outfangthief in English:
outfangthief
(also outfangenetheof, outfangandthef, utfangthef)
noun
Lawhistorical
The right of a lord of a private jurisdiction, more extensive than that of infangthief, to claim for trial a thief, especially one who is the lord's tenant, captured outside the jurisdiction, and to keep any forfeited chattels on conviction; occasionally used to denote the thief so apprehended. Also, more widely: the right of a lord to try any thief apprehended within that lord's jurisdiction, regardless of the accused person's place of origin.
Origin
Old English; earliest use found in Royal Charter: Edgar to Glastonbury. From out [preposition, interjection] + fangen, past participle of fōn + thief, after infangthief.