1. Concerning something that is permissible; tolerable: Doug was sick on the day of an exam, so it was allowable that he could take it after returning to school again.
2. Pertaining to something which is worthy of being considered: The three inches extra in the cotton fabric were an allowable measurement in case of shrinkage after washing.
3. Referring to items that are deductible according to the law: The expenses that Mr. Straight had were allowable tax write-offs.