Definition of "allowable"

allowable

/əˈlaʊ.əbəl/

adjective
comparative more allowable, superlative most allowable
1. Appropriate; satisfactory; acceptable.
2. Intellectually admissible; valid; probable.
3. Able to be added or deducted in consideration of something.
4. Permissible; tolerable; legitimate.
  Quotations
  And first, although there were more things in nature then words which did expresse them, yet even in these mute and silent discourses, to expresse complexed significations, they took a liberty to compound and piece together creatures of allowable formes unto mixtures inexistent […]
  1650, Thomas Browne, Pseudodoxia Epidemica: […], 2nd edition, London: […] A[braham] Miller, for Edw[ard] Dod and Nath[aniel] Ekins, […]
5. (obsolete) Praiseworthy.
noun
plural allowables
1. A permitted amount or activity.