from The Century Dictionary.
- noun In the medieval church in England, an office-book containing the offices for the canonical hours.
Sorry, no etymologies found.
To the church of St. Mary's, Nottingham, the vicar leaves a Golden Legend, a Polichronicon, besides Pupilla Oculi, and a portiforium to Wragby Church, and a missal to Snenton Church (1476).
Lat. portiforium, a breviary, lit. what one carries outside, a portable prayer-book --