permissible

adj

1. permitted.

   “[...] Mr. M. N. Rollason points out that on four-track lines on which the fast lines, in the centre, are flanked by the slow lines, and running at speed is permissible on all four, the traveller can enjoy some quite exciting experiences when trains are doing a "neck-and-neck" on adjacent lines.”

   “The units will be allowed to run up to 90 m.p.h. between Chelmsford and Colchester, but their maximum speed of 100 m.p.h. is not permissible on the G.E. line.”

   “Tony Bowen, of Brigade Electronics, a firm that spent three years developing a “quiet vehicle sounder”, said permissible frequencies and modulation under the regulation make it clear that the Avas should mimic an internal combustion engine.”

2. (uncommon)permissive

   “As regards the incorporation of anglicisms and despite the efforts of the Real Academia Española (an official regulatory body which aims at the purity of the language), Spanish has usually been considered a rather permissible language.”

   “Japanese zoning is specified at a national level, and while local governments do have some control over their local developments, the end result is a zoning code that is very permissible compared to most other countries.”