permissable

Adjective

permissible (comparative more permissible, superlative most permissible)

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.1944 May and June, “Notes and News: Express Travel on Slow Lines”, in Railway Magazine, page 184

   Synonyms:

   acceptable, allowable, legitimate, legit, leveful, licit, rightful, rulable, true, valid

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.2016 December, Marisa Diez-Arroyo, “Vagueness: A loanword’s good friend. The case of ‘Print’ in Spanish fashion”, in Pragmatics, page 609

   Synonyms:

   lax, lenient, clement, easygoing, forbearing, indulgent, loose-handed, permissive, relaxed, remissful

See all 3 meanings of permissible